diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8ce082d7..1691b5a8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,18 +20,43 @@ on:
   workflow_dispatch:
 
 jobs:
-  # When CMake can support disabling check types and
-  # encoders/decoders/threads, it will be combined to one Linux job
-  # and another matrix list.
-  Linux-Autotools:
-    # Just run on latest ubuntu
-    runs-on: ubuntu-latest
+  POSIX:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        build_system: [autotools, cmake]
+    runs-on: ${{ matrix.os }}
     steps:
-      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
+
+      ########################
+      # Install Dependencies #
+      ########################
+
+      # Install Autotools on Linux
       - name: Install Dependencies
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
         run: sudo apt-get install -y autoconf automake build-essential po4a autopoint gcc-multilib doxygen
 
+      # Install Autotools on Mac
+      - name: Install Dependencies
+        if: ${{ matrix.os == 'macos-latest' && matrix.build_system == 'autotools' }}
+        run: brew install autoconf automake libtool po4a doxygen
+
+      # Install CMake on Linux
+      - name: Install Dependencies
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'cmake' }}
+        run: sudo apt-get install -y build-essential cmake
+
+      # Install CMake on Mac
+      - name: Install Dependencies
+        if: ${{ matrix.os == 'macos-latest' && matrix.build_system == 'cmake' }}
+        run: brew install cmake
+
+      ##################
+      # Build and Test #
+      ##################
+
       # -b specifies the build system to use.
       # -p specifies the phase (build or test) to help narrow down an error
       #    if one occurs.
@@ -39,146 +64,62 @@ jobs:
       # Start with the 32-bit build because the autoconf cache must be reset
       # after the build because the 32-bit build sets the CFLAGS env variable.
       # By starting with the 32-bit build, we only have to clear the
-      # cache once.
+      # cache once. The 32-bit build is only tested on Autotools Linux.
       - name: Build 32-bit
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
         run: ./build-aux/ci_build.sh -b autotools -p build -f "-m32"
       - name: Test 32-bit
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
         run: |
             ./build-aux/ci_build.sh -b autotools -p test -f "-m32" -n 32_bit
             cd ../xz_build && make distclean
 
       - name: Build with full features
-        run: ./build-aux/ci_build.sh -b autotools -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -p build
       - name: Test with full features
-        run: ./build-aux/ci_build.sh -b autotools -p test -n full_features
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -p test -n full_features
 
       - name: Build without encoders
-        run: ./build-aux/ci_build.sh -b autotools -d encoders,shared -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d encoders,shared -p build
       - name: Test without encoders
-        run: ./build-aux/ci_build.sh -b autotools -d encoders,shared -p test -n no_encoders
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d encoders,shared -p test -n no_encoders
 
       - name: Build without decoders
-        run: ./build-aux/ci_build.sh -b autotools -d decoders,shared -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d decoders,shared -p build
       - name: Test without decoders
-        run: ./build-aux/ci_build.sh -b autotools -d decoders,shared -p test -n no_decoders
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d decoders,shared -p test -n no_decoders
 
+      # Our CMake build cannot disable threads yet.
       - name: Build without threads
-        run: ./build-aux/ci_build.sh -b autotools -d threads,shared -p build
+        if: ${{ matrix.build_system == 'autotools' }}
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d threads,shared -p build
       - name: Test without threads
-        run: ./build-aux/ci_build.sh -b autotools -d threads,shared -p test -n no_threads
+        if: ${{ matrix.build_system == 'autotools' }}
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d threads,shared -p test -n no_threads
 
       - name: Build without BCJ filters
-        run: ./build-aux/ci_build.sh -b autotools -d bcj,shared,nls -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d bcj,shared,nls -p build
       - name: Test without BCJ filters
-        run: ./build-aux/ci_build.sh -b autotools -d bcj,shared,nls -p test -n no_bcj
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d bcj,shared,nls -p test -n no_bcj
 
       - name: Build without Delta filters
-        run: ./build-aux/ci_build.sh -b autotools -d delta,shared,nls -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d delta,shared,nls -p build
       - name: Test without Delta filters
-        run: ./build-aux/ci_build.sh -b autotools -d delta,shared,nls -p test -n no_delta
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -d delta,shared,nls -p test -n no_delta
 
       - name: Build without sha256 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,crc64 -d shared,nls -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -c crc32,crc64 -d shared,nls -p build
       - name: Test without sha256 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,crc64 -d shared,nls -p test -n no_sha256
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -c crc32,crc64 -d shared,nls -p test -n no_sha256
 
       - name: Build without crc64 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,sha256 -d shared,nls -p build
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -c crc32,sha256 -d shared,nls -p build
       - name: Test without crc64 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,sha256 -d shared,nls -p test -n no_crc64
+        run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -c crc32,sha256 -d shared,nls -p test -n no_crc64
 
       # Attempt to upload the test logs as artifacts if any step has failed
       - uses: actions/upload-artifact@v3
         if: ${{ failure() }}
         with:
-          name: Linux Autotools Test Logs
-          path: build-aux/artifacts
-
-  Linux-CMake:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Install Dependencies
-        run: sudo apt-get install -y build-essential cmake
-      - name: Build
-        run: ./build-aux/ci_build.sh -b cmake -p build
-      - name: Test
-        run: ./build-aux/ci_build.sh -b cmake -p test
-      # Attempt to upload the test logs as artifacts if any step has failed
-      - uses: actions/upload-artifact@v3
-        if: ${{ failure() }}
-        with:
-          name: Linux CMake Test Logs
-          path: build-aux/artifacts
-
-  MacOS-Autotools:
-    runs-on: macos-latest
-    steps:
-      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
-      - name: Install Dependencies
-        run: brew install autoconf automake libtool po4a doxygen
-
-      - name: Build with full features
-        run: ./build-aux/ci_build.sh -b autotools -p build
-      - name: Test with full features
-        run: ./build-aux/ci_build.sh -b autotools -p test -n full_features
-
-      - name: Build without encoders
-        run: ./build-aux/ci_build.sh -b autotools -d encoders,shared -p build
-      - name: Test without encoders
-        run: ./build-aux/ci_build.sh -b autotools -d encoders,shared -p test -n no_encoders
-
-      - name: Build without decoders
-        run: ./build-aux/ci_build.sh -b autotools -d decoders,shared -p build
-      - name: Test without decoders
-        run: ./build-aux/ci_build.sh -b autotools -d decoders,shared -p test -n no_decoders
-
-      - name: Build without threads
-        run: ./build-aux/ci_build.sh -b autotools -d threads,shared -p build
-      - name: Test without threads
-        run: ./build-aux/ci_build.sh -b autotools -d threads,shared -p test -n no_threads
-
-      - name: Build without BCJ filters
-        run: ./build-aux/ci_build.sh -b autotools -d bcj,shared,nls -p build
-      - name: Test without BCJ filters
-        run: ./build-aux/ci_build.sh -b autotools -d bcj,shared,nls -p test -n no_bcj
-
-      - name: Build without Delta filters
-        run: ./build-aux/ci_build.sh -b autotools -d delta,shared,nls -p build
-      - name: Test without Delta filters
-        run: ./build-aux/ci_build.sh -b autotools -d delta,shared,nls -p test -n no_delta
-
-      - name: Build without sha256 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,crc64 -d shared,nls -p build
-      - name: Test without sha256 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,crc64 -d shared,nls -p test -n no_sha256
-
-      - name: Build without crc64 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,sha256 -d shared,nls -p build
-      - name: Test without crc64 check
-        run: ./build-aux/ci_build.sh -b autotools -c crc32,sha256 -d shared,nls -p test -n no_crc64
-
-      # Attempt to upload the test logs as artifacts if any step has failed
-      - uses: actions/upload-artifact@v3
-        if: ${{ failure() }}
-        with:
-          name: MacOS Autotools Test Logs
-          path: build-aux/artifacts
-
-  MacOS-CMake:
-    runs-on: macos-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Install Dependencies
-        run: brew install cmake
-      - name: Build
-        run: ./build-aux/ci_build.sh -b cmake -p build
-      - name: Test
-        run: ./build-aux/ci_build.sh -b cmake -p test
-      # Attempt to upload the test logs as artifacts if any step has failed
-      - uses: actions/upload-artifact@v3
-        if: ${{ failure() }}
-        with:
-          name: MacOS CMake Test Logs
+          name: ${{ matrix.os }} ${{ matrix.build_system }} Test Logs
           path: build-aux/artifacts