diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 00000000..a46193bb
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,55 @@
+name: analyze pyqtgraph
+
+on: pull_request
+
+jobs:
+  analyze:
+    name: analyze
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        # We must fetch at least the immediate parents so that if this is
+        # a pull request then we can checkout the head.
+        fetch-depth: 2
+    - name: Setup Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.9'
+    - name: Install Dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install PyQt5 numpy scipy six
+        echo "CODEQL_PYTHON=$(which python)" >> $GITHUB_ENV
+    
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: 'python'
+        # Supported options are ['csharp', 'cpp', 'go', 'java', 'javascript', 'python']
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        queries: +security-and-quality
+        setup-python-dependencies: false
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 00000000..e4c7f10c
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,166 @@
+name: test pyqtgraph
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        qt-lib: [pyqt5, pyside2]
+        python-version: [3.7, 3.8, 3.9]
+        include:
+          - python-version: "3.7"
+            qt-version: "~=5.12.0"
+            numpy-version: "~=1.17.0"
+          - python-version: "3.8"
+            qt-version: "~=5.15.0"
+            numpy-version: "~=1.19.0"
+          - python-version: "3.9"
+            qt-version: ""
+            numpy-version: ""
+    steps:
+    - uses: actions/checkout@v2
+    - name: Setup Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        # Semantic version range syntax or exact version of a Python version
+        python-version: ${{ matrix.python-version }}
+    - name: "Install Windows-Mesa OpenGL DLL"
+      if: runner.os == 'Windows'
+      run: |
+        curl -LJO https://github.com/pal1000/mesa-dist-win/releases/download/19.2.7/mesa3d-19.2.7-release-msvc.7z
+        7z x mesa3d-19.2.7-release-msvc.7z
+        cd x64
+        xcopy opengl32.dll C:\windows\system32\mesadrv.dll*
+        xcopy opengl32.dll C:\windows\syswow64\mesadrv.dll*
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DLL /t REG_SZ /d "mesadrv.dll" /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DriverVersion /t REG_DWORD /d 1 /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Flags /t REG_DWORD /d 1 /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Version /t REG_DWORD /d 2 /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DLL /t REG_SZ /d "mesadrv.dll" /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DriverVersion /t REG_DWORD /d 1 /f
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Flags /t REG_DWORD /d 1 /f 
+        REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Version /t REG_DWORD /d 2 /f 
+      shell: cmd
+    - name: Install Dependencies
+      run: |
+        pip install --upgrade pip
+        pip install ${{ matrix.qt-lib }}${{ matrix.qt-version }} numpy${{ matrix.numpy-version }} scipy pyopengl h5py six matplotlib
+        pip install .
+        pip install pytest pytest-cov pytest-xdist coverage
+    - name: "Install Linux VirtualDisplay"
+      if: runner.os == 'Linux'
+      run: |
+        sudo apt-get install -y libxkbcommon-x11-0 x11-utils
+        sudo apt-get install --no-install-recommends -y libyaml-dev libegl1-mesa libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-xinerama0
+        pip install pytest-xvfb
+    - name: 'Debug Info'
+      run: |
+        echo python location: `which python`
+        echo python version: `python --version`
+        echo pytest location: `which pytest`
+        echo installed packages
+        pip list
+        echo pyqtgraph system info
+        python -c "import pyqtgraph as pg; pg.systemInfo()"
+      shell: bash
+      env:
+        QT_DEBUG_PLUGINS: 1
+    - name: 'XVFB Display Info'
+      run: |
+        xvfb-run --server-args="-screen 0, 1920x1200x24 -ac +extension GLX +render -noreset" python -c "from pyqtgraph.opengl.glInfo import GLTest"
+        xvfb-run --server-args="-screen 0, 1920x1200x24 -ac +extension GLX +render -noreset" python -m pyqtgraph.util.get_resolution
+      if: runner.os == 'Linux'
+    - name: 'Display Info'
+      run: |
+        python -c "from pyqtgraph.opengl.glInfo import GLTest"
+        python -m pyqtgraph.util.get_resolution
+      if: runner.os != 'Linux'
+    - name: Run Tests
+      run: |
+        mkdir $SCREENSHOT_DIR
+        pytest . -v \
+          -n auto \
+          --junitxml=junit/test-results.xml \
+          --cov pyqtgraph --cov-report=xml --cov-report=html
+      shell: bash
+    - name: Upload Screenshots
+      uses: actions/upload-artifact@v2
+      with:
+        name: Screenshots (Python ${{ matrix.python-version }} - Qt-Bindings ${{ matrix.qt-lib }} - OS ${{ matrix.os }})
+        path: $SCREENSHOT_DIR
+        if-no-files-found: ignore
+    - name: Upload Unit Test Results
+      if: always()
+      uses: actions/upload-artifact@v2
+      with:
+        name: Unit Test Results (Python ${{ matrix.python-version }} - Qt-Bindings ${{ matrix.qt-lib }} - OS ${{ matrix.os }})
+        path: junit/test-results.xml
+    env:
+      SCREENSHOT_DIR: ./screenshots
+
+  build-docs:
+    name: build docs
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+      - name: Install Dependencies
+        run: |
+          cd doc
+          python -m pip install -r requirements.txt
+      - name: Build Documentation
+        run: |
+          cd doc
+          make html SPHINXOPTS='-W -v'
+      - name: Upload Build Docs
+        uses: actions/upload-artifact@v2
+        with:
+          name: html-docs
+          path: |
+            doc/build/html
+    
+  linting:
+    name: check linting
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+      - name: "Install Dependencies"
+        run: |
+          pip install flake8
+      - name: "Check Linting"
+        run: |
+          python -m flake8 .
+
+  build-wheel:
+    name: build wheel
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+      - name: Build Wheel
+        run: |
+          python -m pip install setuptools wheel
+          python setup.py bdist_wheel
+      - name: Archive pyqtgraph wheel
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheel
+          path: |
+            dist
diff --git a/README.md b/README.md
index c86f5445..88f2a78c 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,14 @@
-
-[![Build Status](https://pyqtgraph.visualstudio.com/pyqtgraph/_apis/build/status/pyqtgraph.pyqtgraph?branchName=master)](https://pyqtgraph.visualstudio.com/pyqtgraph/_build/latest?definitionId=17&branchName=master)
-[![Documentation Status](https://readthedocs.org/projects/pyqtgraph/badge/?version=latest)](https://pyqtgraph.readthedocs.io/en/latest/?badge=latest)
-
 PyQtGraph
 =========
 
+[![PyPi](https://img.shields.io/pypi/v/pyqtgraph.svg)](https://pypi.org/project/pyqtgraph/)
+[![conda-forge](https://img.shields.io/conda/vn/conda-forge/pyqtgraph.svg)](https://anaconda.org/conda-forge/pyqtgraph)
+[![Build Status](https://github.com/pyqtgraph/pyqtgraph/workflows/main/badge.svg)](https://github.com/pyqtgraph/pyqtgraph/workflows/main/badge.svg)
+[![CodeQL Status](https://github.com/pyqtgraph/pyqtgraph/workflows/codeql-analysis/badge.svg)](https://github.com/pyqtgraph/pyqtgraph/workflows/codeql-analysis/badge.svg)
+[![Documentation Status](https://readthedocs.org/projects/pyqtgraph/badge/?version=latest)](https://pyqtgraph.readthedocs.io/en/latest/?badge=latest)
+[![Total alerts](https://img.shields.io/lgtm/alerts/g/pyqtgraph/pyqtgraph.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/pyqtgraph/pyqtgraph/alerts/)
+[![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/pyqtgraph/pyqtgraph.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/pyqtgraph/pyqtgraph/context:python)
+
 A pure-Python graphics library for PyQt5/PySide2
 
 Copyright 2020 Luke Campagnola, University of North Carolina at Chapel Hill
@@ -24,21 +28,20 @@ pyqtgraph has adopted [NEP 29](https://numpy.org/neps/nep-0029-deprecation_polic
 This project supports:
 
 * All minor versions of Python released 42 months prior to the project, and at minimum the two latest minor versions.
-
 * All minor versions of numpy released in the 24 months prior to the project, and at minimum the last three minor versions.
 * All minor versions of Qt 5 currently supported by upstream Qt (Note, Qt 6 support is not yet implemented)
 
-
 Currently this means:
 
 * Python 3.7+
-* Qt 5.12, 5.15
+* Qt 5.12-5.15
 * Required
-  * PyQt5, or PySide2
+  * PyQt5 or PySide2
   * `numpy` 1.17+
 * Optional
   * `scipy` for image processing
   * `pyopengl` for 3D graphics
+    * `pyopengl` on macOS Big Sur only works with python 3.9.1+
   * `hdf5` for large hdf5 binary format support
 
 Qt Bindings Test Matrix
@@ -46,12 +49,12 @@ Qt Bindings Test Matrix
 
 The following table represents the python environments we test in our CI system.  Our CI system uses Ubuntu 18.04, Windows Server 2019, and macOS 10.15 base images.
 
-| Qt-Bindings    | Python 3.6         | Python 3.7         | Python 3.8         |
+| Qt-Bindings    | Python 3.7         | Python 3.8         | Python 3.9         |
 | :------------- | :----------------: | :----------------: | :----------------: |
-| PyQt5-5.9      | :white_check_mark: | :x:                | :x:                |
-| PySide2-5.13   | :x:                | :white_check_mark: | :x:                |
-| PyQt5-Latest   | :x:                | :x:                | :white_check_mark: |
-| PySide2-Latest | :x:                | :x:                | :white_check_mark: |
+| PySide2-5.12   | :white_check_mark: | :x:                | :x:                |
+| PyQt5-5.12     | :white_check_mark: | :x:                | :x:                |
+| PySide2-5.15   | :x:                | :white_check_mark: | :white_check_mark: |
+| PyQt5-5.15     | :x:                | :white_check_mark: | :white_check_mark: |
 
 Support
 -------
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
deleted file mode 100644
index 5e87923e..00000000
--- a/azure-pipelines.yml
+++ /dev/null
@@ -1,113 +0,0 @@
-trigger:
-  branches:
-    include:
-    - '*' # Build for all branches if they have a azure-pipelines.yml file.
-  tags:
-    include:
-    - 'v*' # Ensure that we are building for tags starting with 'v' (Official Versions)
-
-# Build only for PRs for master branch
-pr:
-  autoCancel: true
-  branches:
-    include:
-      - master
-      - develop
-
-variables:
-  OFFICIAL_REPO: 'pyqtgraph/pyqtgraph'
-  DEFAULT_MERGE_BRANCH: 'master'
-  disable.coverage.autogenerate: 'true'
-
-stages:
-- stage: pre_build
-  jobs:
-  - job: check_diff_size
-    pool:
-      vmImage: 'Ubuntu 18.04'
-    steps:
-    - bash: |
-        git config --global advice.detachedHead false
-        mkdir ~/repo-clone && cd ~/repo-clone
-        git init
-
-        git remote add -t $(Build.SourceBranchName) origin $(Build.Repository.Uri)
-        git remote add -t ${DEFAULT_MERGE_BRANCH} upstream https://github.com/${OFFICIAL_REPO}.git
-
-        git fetch origin $(Build.SourceBranchName)
-        git fetch upstream ${DEFAULT_MERGE_BRANCH}
-
-        git checkout $(Build.SourceBranchName)
-        MERGE_SIZE=`du -s . | sed -e "s/\t.*//"`
-        echo -e "Merge Size ${MERGE_SIZE}"
-
-        git checkout ${DEFAULT_MERGE_BRANCH}
-        TARGET_SIZE=`du -s . | sed -e "s/\t.*//"`
-        echo -e "Target Size ${TARGET_SIZE}"
-
-        if [ "${MERGE_SIZE}" != "${TARGET_SIZE}" ]; then
-          SIZE_DIFF=`expr \( ${MERGE_SIZE} - ${TARGET_SIZE} \)`;
-        else
-          SIZE_DIFF=0;
-        fi;
-        echo -e "Estimated content size difference = ${SIZE_DIFF} kB" &&
-        test ${SIZE_DIFF} -lt 100;
-      displayName: 'Diff Size Check'
-  - job: "style_check"
-    pool:
-      vmImage: "Ubuntu 18.04"
-    steps:
-    - task: UsePythonVersion@0
-      inputs:
-        versionSpec: 3.7
-    - bash: |
-        pip install flake8
-        python setup.py style
-      displayName: 'flake8 check'
-  - job: "build_docs"
-    pool:
-      vmImage: 'Ubuntu 18.04'
-    steps:
-    - task: UsePythonVersion@0
-      inputs:
-        versionSpec: 3.8
-    - script: |
-        cd doc
-        python -m pip install -r requirements.txt
-        make html SPHINXOPTS='-W -v'
-      displayName: "Build docs"
-
-- stage: build
-  dependsOn: []
-  jobs:
-  - job: "build_wheel"
-    pool:
-      vmImage: 'Ubuntu 18.04'
-    steps:
-    - task: UsePythonVersion@0
-      inputs:
-        versionSpec: 3.8
-    - script: |
-        python -m pip install setuptools wheel
-        python setup.py bdist_wheel --universal
-      displayName: "Build Python Wheel"
-      continueOnError: false
-    - publish: dist
-      artifact: wheel
-
-- stage: test
-  displayName: "Test Suite"
-  dependsOn: build
-  jobs:
-  - template: azure-test-template.yml
-    parameters:
-      name: linux
-      vmImage: 'Ubuntu 18.04'
-  - template: azure-test-template.yml
-    parameters:
-      name: windows
-      vmImage: 'windows-2019'
-  - template: azure-test-template.yml
-    parameters:
-      name: macOS
-      vmImage: 'macOS-10.15'
\ No newline at end of file
diff --git a/azure-test-template.yml b/azure-test-template.yml
deleted file mode 100644
index 7ab0dce2..00000000
--- a/azure-test-template.yml
+++ /dev/null
@@ -1,208 +0,0 @@
-# Azure Pipelines CI job template for PyDM Tests
-# https://docs.microsoft.com/en-us/azure/devops/pipelines/languages/anaconda?view=azure-devops
-parameters:
-  name: ''
-  vmImage: ''
-
-jobs:
-- job: ${{ parameters.name }}
-  pool:
-    vmImage: ${{ parameters.vmImage }}
-  strategy:
-    matrix:
-      Python36-PyQt5-5.9:
-        python.version: "3.6"
-        qt.bindings: "pyqt"
-        install.method: "conda"
-      Python37-PySide2-5.13:
-        python.version: "3.7"
-        qt.bindings: "pyside2"
-        install.method: "conda"
-      Python38-PyQt5-Latest:
-        python.version: '3.8'
-        qt.bindings: "PyQt5"
-        install.method: "pip"
-      Python38-PySide2-Latest:
-        python.version: '3.8'
-        qt.bindings: "PySide2"
-        install.method: "pip"     
-
-  steps:
-  - task: DownloadPipelineArtifact@2
-    inputs:
-      source: 'current'
-      artifact: wheel
-      path: 'dist'
-
-  - task: ScreenResolutionUtility@1
-    inputs:
-      displaySettings: 'specific'
-      width: '1920'
-      height: '1080'
-    condition: eq(variables['agent.os'], 'Windows_NT' )
-
-  - task: UsePythonVersion@0
-    inputs:
-      versionSpec: $(python.version)
-    condition: eq(variables['install.method'], 'pip')
-
-  - script: |
-      curl -LJO https://github.com/pal1000/mesa-dist-win/releases/download/19.1.0/mesa3d-19.1.0-release-msvc.exe
-      7z x mesa3d-19.1.0-release-msvc.exe
-      cd x64
-      xcopy opengl32.dll C:\windows\system32\mesadrv.dll*
-      xcopy opengl32.dll C:\windows\syswow64\mesadrv.dll*
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DLL /t REG_SZ /d "mesadrv.dll" /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DriverVersion /t REG_DWORD /d 1 /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Flags /t REG_DWORD /d 1 /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Version /t REG_DWORD /d 2 /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DLL /t REG_SZ /d "mesadrv.dll" /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v DriverVersion /t REG_DWORD /d 1 /f
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Flags /t REG_DWORD /d 1 /f 
-      REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\MSOGL" /v Version /t REG_DWORD /d 2 /f 
-    displayName: "Install Windows-Mesa OpenGL DLL"
-    condition: eq(variables['agent.os'], 'Windows_NT')
-
-  - bash: |
-      if [ $(agent.os) == 'Linux' ]
-      then
-        echo "##vso[task.prependpath]$CONDA/bin"
-      elif [ $(agent.os) == 'Darwin' ]
-      then
-        sudo chown -R $USER $CONDA  
-        echo "##vso[task.prependpath]$CONDA/bin"
-      elif [ $(agent.os) == 'Windows_NT' ]
-      then
-        echo "##vso[task.prependpath]$CONDA/Scripts"
-      else
-        echo 'Just what OS are you using?'
-      fi
-    displayName: 'Add Conda To $PATH' 
-    condition: eq(variables['install.method'], 'conda' )
-    continueOnError: false
-
-  - bash: |
-      if [ $(install.method) == "conda" ]
-      then
-        conda update --all --yes --quiet
-        conda config --env --set always_yes true
-        if [ $(python.version) == '2.7' ]
-        then
-          conda config --set restore_free_channel true
-        fi
-        if [ $(qt.bindings) == "pyside2" ] || ([ $(qt.bindings) == 'pyside' ] && [ $(agent.os) == 'Darwin' ])
-        then
-          conda config --prepend channels conda-forge
-        fi      
-        conda create --name test-environment-$(python.version) python=$(python.version) --yes --quiet
-        source activate test-environment-$(python.version)
-        conda info
-        
-        if [ $(qt.bindings) == "pyside2" ]
-        then
-          conda install $(qt.bindings) --yes --quiet --strict-channel-priority
-        else
-          conda install $(qt.bindings) --yes --quiet
-        fi
-        conda install numpy scipy pyopengl h5py six --yes --quiet
-        pip install matplotlib
-      else
-        pip install $(qt.bindings) numpy scipy pyopengl h5py six matplotlib
-      fi
-      pip install pytest pytest-cov coverage pytest-xdist
-      if [ $(python.version) == "2.7" ]
-      then
-        pip install pytest-faulthandler==1.6.0
-        export PYTEST_ADDOPTS="--faulthandler-timeout=15"
-      else
-        pip install pytest pytest-cov coverage
-      fi
-    displayName: "Install Dependencies"
-
-  - bash: |
-      if [ $(install.method) == "conda" ]
-      then
-        source activate test-environment-$(python.version)
-      fi
-      python -m pip install --no-index --find-links=dist pyqtgraph
-    displayName: 'Install Wheel'
-
-  - bash: |
-      sudo apt-get install -y libxkbcommon-x11-dev 
-      # workaround for QTBUG-84489
-      sudo apt-get install -y libxcb-xfixes0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-xinerama0
-      if [ $(install.method) == "conda" ]
-      then
-        source activate test-environment-$(python.version)
-      fi
-      if [ $(python.version) == "2.7" ]
-      then
-        pip install PyVirtualDisplay==0.2.5 pytest-xvfb==1.2.0
-      else
-        pip install pytest-xvfb
-      fi
-    displayName: "Virtual Display Setup"
-    condition: eq(variables['agent.os'], 'Linux' )
-
-  - bash: |
-      export QT_DEBUG_PLUGINS=1
-      if [ $(install.method) == "conda" ]
-      then
-        source activate test-environment-$(python.version)
-      fi
-      echo python location: `which python`
-      echo python version: `python --version`
-      echo pytest location: `which pytest`
-      echo installed packages
-      pip list
-      echo pyqtgraph system info
-      python -c "import pyqtgraph as pg; pg.systemInfo()"
-      echo display information
-      if [ $(agent.os) == 'Linux' ]
-      then
-        export DISPLAY=:99.0
-        Xvfb :99 -screen 0 1920x1200x24 -ac +extension GLX +render -noreset &
-        sleep 3
-      fi
-      python -m pyqtgraph.util.get_resolution
-      echo openGL information
-      python -c "from pyqtgraph.opengl.glInfo import GLTest"
-    displayName: 'Debug Info'
-    continueOnError: false
-
-  - bash: |
-      if [ $(install.method) == "conda" ]
-      then
-        source activate test-environment-$(python.version)
-      fi
-      mkdir -p "$SCREENSHOT_DIR"
-      # echo "If Screenshots are generated, they may be downloaded from:"
-      # echo "https://dev.azure.com/pyqtgraph/pyqtgraph/_apis/build/builds/$(Build.BuildId)/artifacts?artifactName=Screenshots&api-version=5.0"
-      pytest . -v \
-        -n 1 \
-        --junitxml=junit/test-results.xml \
-        --cov pyqtgraph --cov-report=xml --cov-report=html
-    displayName: 'Unit tests' 
-    env:
-      AZURE: 1
-      SCREENSHOT_DIR: $(Build.ArtifactStagingDirectory)/screenshots
-      
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish Screenshots' 
-    condition: failed()
-    inputs:
-      pathtoPublish: $(Build.ArtifactStagingDirectory)/screenshots
-      artifactName: Screenshots
-  
-  - task: PublishTestResults@2
-    condition: succeededOrFailed()
-    inputs:
-      testResultsFiles: '**/test-*.xml'
-      testRunTitle: 'Test Results for $(agent.os) - $(python.version) - $(qt.bindings) - $(install.method)'
-      publishRunAttachments: true
-  
-  - task: PublishCodeCoverageResults@1
-    inputs:
-      codeCoverageTool: Cobertura
-      summaryFileLocation: '$(System.DefaultWorkingDirectory)/**/coverage.xml'
-      reportDirectory: '$(System.DefaultWorkingDirectory)/**/htmlcov'
diff --git a/examples/ExampleApp.py b/examples/ExampleApp.py
index ea98373f..ef280979 100644
--- a/examples/ExampleApp.py
+++ b/examples/ExampleApp.py
@@ -1,4 +1,6 @@
+import keyword
 import os
+import re
 import sys
 import subprocess
 import pyqtgraph as pg
@@ -104,7 +106,7 @@ examples = OrderedDict([
 
 # based on https://github.com/art1415926535/PyQt5-syntax-highlighting
 
-QRegExp = QtCore.QRegExp
+QRegularExpression = QtCore.QRegularExpression
 
 QFont = QtGui.QFont
 QColor = QtGui.QColor
@@ -208,55 +210,45 @@ class PythonHighlighter(QSyntaxHighlighter):
     """Syntax highlighter for the Python language.
     """
     # Python keywords
-    keywords = [
-        'and', 'assert', 'break', 'class', 'continue', 'def',
-        'del', 'elif', 'else', 'except', 'exec', 'finally',
-        'for', 'from', 'global', 'if', 'import', 'in',
-        'is', 'lambda', 'not', 'or', 'pass', 'print',
-        'raise', 'return', 'try', 'while', 'yield',
-        'None', 'True', 'False', 'async', 'await',
-    ]
+    keywords = keyword.kwlist
 
     # Python operators
     operators = [
-        '=',
+        r'=',
         # Comparison
-        '==', '!=', '<', '<=', '>', '>=',
+        r'==', r'!=', r'<', r'<=', r'>', r'>=',
         # Arithmetic
-        '\+', '-', '\*', '/', '//', '\%', '\*\*',
+        r'\+', r"-", r'\*', r'/', r'//', r'%', r'\*\*',
         # In-place
-        '\+=', '-=', '\*=', '/=', '\%=',
+        r'\+=', r'-=', r'\*=', r'/=', r'\%=',
         # Bitwise
-        '\^', '\|', '\&', '\~', '>>', '<<',
+        r'\^', r'\|', r'&', r'~', r'>>', r'<<',
     ]
 
     # Python braces
     braces = [
-        '\{', '\}', '\(', '\)', '\[', '\]',
+        r'\{', r'\}', r'\(', r'\)', r'\[', r'\]',
     ]
 
     def __init__(self, document):
         QSyntaxHighlighter.__init__(self, document)
 
         # Multi-line strings (expression, flag, style)
-        # FIXME: The triple-quotes in these two lines will mess up the
-        # syntax highlighting from this point onward
-        self.tri_single = (QRegExp("'''"), 1, 'string2')
-        self.tri_double = (QRegExp('"""'), 2, 'string2')
+        self.tri_single = (QRegularExpression("'''"), 1, 'string2')
+        self.tri_double = (QRegularExpression('"""'), 2, 'string2')
 
         rules = []
 
         # Keyword, operator, and brace rules
         rules += [(r'\b%s\b' % w, 0, 'keyword')
                   for w in PythonHighlighter.keywords]
-        rules += [(r'%s' % o, 0, 'operator')
+        rules += [(o, 0, 'operator')
                   for o in PythonHighlighter.operators]
-        rules += [(r'%s' % b, 0, 'brace')
+        rules += [(b, 0, 'brace')
                   for b in PythonHighlighter.braces]
 
         # All other rules
         rules += [
-
             # 'self'
             (r'\bself\b', 0, 'self'),
 
@@ -277,12 +269,8 @@ class PythonHighlighter(QSyntaxHighlighter):
 
             # From '#' until a newline
             (r'#[^\n]*', 0, 'comment'),
-
         ]
-
-        # Build a QRegExp for each pattern
-        self.rules = [(QRegExp(pat), index, fmt)
-                      for (pat, index, fmt) in rules]
+        self.rules = rules
 
     @property
     def styles(self):
@@ -294,16 +282,14 @@ class PythonHighlighter(QSyntaxHighlighter):
         """
         # Do other syntax formatting
         for expression, nth, format in self.rules:
-            index = expression.indexIn(text, 0)
             format = self.styles[format]
 
-            while index >= 0:
-                # We actually want the index of the nth match
-                index = expression.pos(nth)
-                length = len(expression.cap(nth))
-                self.setFormat(index, length, format)
-                index = expression.indexIn(text, index + length)
-
+            for n, match in enumerate(re.finditer(expression, text)):
+                if n < nth:
+                    continue
+                start = match.start()
+                length = match.end() - start
+                self.setFormat(start, length, format)
         self.setCurrentBlockState(0)
 
         # Do multi-line strings
@@ -312,11 +298,16 @@ class PythonHighlighter(QSyntaxHighlighter):
             in_multiline = self.match_multiline(text, *self.tri_double)
 
     def match_multiline(self, text, delimiter, in_state, style):
-        """Do highlighting of multi-line strings. ``delimiter`` should be a
-        ``QRegExp`` for triple-single-quotes or triple-double-quotes, and
-        ``in_state`` should be a unique integer to represent the corresponding
-        state changes when inside those strings. Returns True if we're still
-        inside a multi-line string when this function is finished.
+        """Do highlighting of multi-line strings. 
+        
+        =========== ==========================================================
+        delimiter   (QRegularExpression) for triple-single-quotes or 
+                    triple-double-quotes
+        in_state    (int) to represent the corresponding state changes when 
+                    inside those strings. Returns True if we're still inside a
+                    multi-line string when this function is finished.
+        style       (str) representation of the kind of style to use
+        =========== ==========================================================
         """
         # If inside triple-single quotes, start at 0
         if self.previousBlockState() == in_state:
@@ -324,17 +315,19 @@ class PythonHighlighter(QSyntaxHighlighter):
             add = 0
         # Otherwise, look for the delimiter on this line
         else:
-            start = delimiter.indexIn(text)
+            match = delimiter.match(text)
+            start = match.capturedStart()
             # Move past this match
-            add = delimiter.matchedLength()
+            add = match.capturedLength()
 
         # As long as there's a delimiter match on this line...
         while start >= 0:
             # Look for the ending delimiter
-            end = delimiter.indexIn(text, start + add)
+            match = delimiter.match(text, start + add)
+            end = match.capturedEnd()
             # Ending delimiter on this line?
             if end >= add:
-                length = end - start + add + delimiter.matchedLength()
+                length = end - start + add + match.capturedLength()
                 self.setCurrentBlockState(0)
             # No; multi-line string
             else:
@@ -343,7 +336,8 @@ class PythonHighlighter(QSyntaxHighlighter):
             # Apply formatting
             self.setFormat(start, length, self.styles[style])
             # Look for the next match
-            start = delimiter.indexIn(text, start + length)
+            match = delimiter.match(text, start + length)
+            start = match.capturedStart()
 
         # Return True if still inside a multi-line string, False otherwise
         if self.currentBlockState() == in_state:
diff --git a/examples/test_examples.py b/examples/test_examples.py
index 685b71d7..a0be0750 100644
--- a/examples/test_examples.py
+++ b/examples/test_examples.py
@@ -10,6 +10,7 @@ import importlib
 import itertools
 import pytest
 import os, sys
+import platform
 import subprocess
 import time
 if __name__ == "__main__" and (__package__ is None or __package__==''):
@@ -69,75 +70,83 @@ conditionalExamples = {
         )
     ),
     'GLVolumeItem.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLIsosurface.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLSurfacePlot.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLScatterPlotItem.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLshaders.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLLinePlotItem.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLMeshItem.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     ),
     'GLImageItem.py': exceptionCondition(
-        not(sys.platform == "darwin" and
-            sys.version_info[0] == 2 and
-            (frontends[Qt.PYQT4] or frontends[Qt.PYSIDE])),
+        not(platform.system() == "Darwin" and
+            tuple(map(int, platform.mac_ver()[0].split("."))) >= (10, 16) and 
+            (sys.version_info <= (3, 8, 7) or
+            (sys.version_info >= (3, 9) and sys.version_info < (3, 9, 1)))),
         reason=(
-            "glClear does not work on macOS + Python2.7 + Qt4: ",
-            "https://github.com/pyqtgraph/pyqtgraph/issues/939"
+            "pyopenGL cannot find openGL libray on big sur: "
+            "https://github.com/python/cpython/pull/21241"
         )
     )
 }
diff --git a/pyqtgraph/functions.py b/pyqtgraph/functions.py
index a2949ef7..fb716904 100644
--- a/pyqtgraph/functions.py
+++ b/pyqtgraph/functions.py
@@ -38,7 +38,7 @@ SI_PREFIXES_ASCII = 'yzafpnum kMGTPEZY'
 SI_PREFIX_EXPONENTS = dict([(SI_PREFIXES[i], (i-8)*3) for i in range(len(SI_PREFIXES))])
 SI_PREFIX_EXPONENTS['u'] = -6
 
-FLOAT_REGEX = re.compile(r'(?P<number>[+-]?((((\d+(\.\d*)?)|(\d*\.\d+))([eE][+-]?\d+)?)|((?i)(nan)|(inf))))\s*((?P<siPrefix>[u' + SI_PREFIXES + r']?)(?P<suffix>\w.*))?$')
+FLOAT_REGEX = re.compile(r'(?P<number>[+-]?((((\d+(\.\d*)?)|(\d*\.\d+))([eE][+-]?\d+)?)|((?i:nan)|(inf))))\s*((?P<siPrefix>[u' + SI_PREFIXES + r']?)(?P<suffix>\w.*))?$')
 INT_REGEX = re.compile(r'(?P<number>[+-]?\d+)\s*(?P<siPrefix>[u' + SI_PREFIXES + r']?)(?P<suffix>.*)$')
 
     
diff --git a/pyqtgraph/tests/image_testing.py b/pyqtgraph/tests/image_testing.py
index cfb62bb9..12101b2c 100644
--- a/pyqtgraph/tests/image_testing.py
+++ b/pyqtgraph/tests/image_testing.py
@@ -212,7 +212,7 @@ def assertImageApproved(image, standardFile, message=None, **kwargs):
             else:
                 if os.getenv('TRAVIS') is not None:
                     saveFailedTest(image, stdImage, standardFile, upload=True)
-                elif os.getenv('AZURE') is not None:
+                elif os.getenv('CI') is not None:
                     standardFile = os.path.join(os.getenv("SCREENSHOT_DIR", "screenshots"), standardFile)
                     saveFailedTest(image, stdImage, standardFile)
                 print(graphstate)
@@ -509,7 +509,7 @@ def getTestDataRepo():
         if not os.path.isdir(parentPath):
             os.makedirs(parentPath)
 
-        if os.getenv('TRAVIS') is not None or os.getenv('AZURE') is not None:
+        if os.getenv('TRAVIS') is not None or os.getenv('CI') is not None:
             # Create a shallow clone of the test-data repository (to avoid
             # downloading more data than is necessary)
             os.makedirs(dataPath)
diff --git a/pyqtgraph/tests/test_reload.py b/pyqtgraph/tests/test_reload.py
index 934d2ed2..11b12cf2 100644
--- a/pyqtgraph/tests/test_reload.py
+++ b/pyqtgraph/tests/test_reload.py
@@ -1,6 +1,7 @@
 import tempfile, os, sys, shutil, time
 import pyqtgraph as pg
 import pyqtgraph.reload
+import pytest
 
 
 pgpath = os.path.join(os.path.dirname(pg.__file__), '..')
@@ -41,7 +42,11 @@ def remove_cache(mod):
     if os.path.isdir(cachedir):
         shutil.rmtree(cachedir)
 
-
+@pytest.mark.skipif(
+    pg.Qt.QT_LIB == "PySide2"
+    and pg.Qt.PySide2.__version__.startswith("5.15")
+    and sys.version_info > (3, 9),
+    reason="Unknown Issue")
 def test_reload():
     py3 = sys.version_info >= (3,)
 
diff --git a/pyqtgraph/widgets/MatplotlibWidget.py b/pyqtgraph/widgets/MatplotlibWidget.py
index c5b6c980..232918ee 100644
--- a/pyqtgraph/widgets/MatplotlibWidget.py
+++ b/pyqtgraph/widgets/MatplotlibWidget.py
@@ -1,7 +1,7 @@
 from ..Qt import QtGui, QtCore, QT_LIB
 import matplotlib
 
-if QT_LIB != 'PyQt5':
+if QT_LIB not in ['PyQt5', "PySide2"]:
     if QT_LIB == 'PySide':
         matplotlib.rcParams['backend.qt4']='PySide'
 
diff --git a/pytest.ini b/pytest.ini
index 355e9dfd..a16534bd 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -16,4 +16,6 @@ filterwarnings =
     # py36/pyside2_512 specific issue
     ignore:split\(\) requires a non-empty pattern match\.:FutureWarning
     # pyqtgraph specific warning we want to ignore during testing
-    ignore:Visible window deleted. To prevent this, store a reference to the window object.
\ No newline at end of file
+    ignore:Visible window deleted. To prevent this, store a reference to the window object.
+    # xvfb warnings
+    ignore:Unknown config option:pytest.PytestConfigWarning
diff --git a/tools/setupHelpers.py b/tools/setupHelpers.py
index 642c5d77..63b255d3 100644
--- a/tools/setupHelpers.py
+++ b/tools/setupHelpers.py
@@ -379,7 +379,7 @@ def getGitVersion(tagPrefix):
                       'describe',
                       '--tags',
                       '--dirty',
-                      '--match=%s*'%tagPrefix]).strip().decode('utf-8')
+                      '--match="%s*"'%tagPrefix]).strip().decode('utf-8')
 
     # chop off prefix
     assert v.startswith(tagPrefix)