diff --git a/.github/workflows/build-majestic.yml b/.github/workflows/build-majestic.yml
index 4acfc244b..c72618d91 100644
--- a/.github/workflows/build-majestic.yml
+++ b/.github/workflows/build-majestic.yml
@@ -2,27 +2,19 @@ name: Build majestic runtime
 
 on: push
 
+env:
+  LD_LIBRARY_PATH: /usr/local/lib
+
 jobs:
 
-  ubuntu:
-    name: Build on Ubuntu
+  ubuntu-runtime:
+    name: Runtime (Ubuntu)
     runs-on: ubuntu-20.04
 
     steps:
     - uses: actions/checkout@v2
 
-    # All these are already available in GitHub runner
-    # - name: Install build tools
-    #   run: |
-    #     sudo apt-get update
-    #     sudo apt-get install -y \
-    #       autoconf \
-    #       automake \
-    #       libtool \
-    #       make \
-    #       g++
-
-    - name: Build C runtime
+    - name: Build runtime
       working-directory: ./src/runtime/c
       run: |
         autoreconf -i
@@ -30,37 +22,141 @@ jobs:
         make
         sudo make install
 
+    - name: Upload artifact
+      uses: actions/upload-artifact@master
+      with:
+        name: libpgf-ubuntu
+        path: |
+          /usr/local/lib/libpgf*
+          /usr/local/include/pgf
+
+  ubuntu-haskell:
+    name: Haskell (Ubuntu)
+    runs-on: ubuntu-20.04
+    needs: ubuntu-runtime
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Download artifact
+      uses: actions/download-artifact@master
+      with:
+        name: libpgf-ubuntu
+    - run: |
+        sudo mv lib/* /usr/local/lib/
+        sudo mv include/* /usr/local/include/
+
     - name: Setup Haskell
       uses: haskell/actions/setup@v1
-      # with:
-      #   ghc-version: '8.6'
-      #   cabal-version: '2.4.1.0'
 
-    - name: Run Haskell testsuite
+    - name: Build & run testsuite
       working-directory: ./src/runtime/haskell
-      env:
-        LD_LIBRARY_PATH: /usr/local/lib
       run: |
         cabal test --extra-lib-dirs=/usr/local/lib
 
-    - name: Install Python bindings
+  ubuntu-python:
+    name: Python (Ubuntu)
+    runs-on: ubuntu-20.04
+    needs: ubuntu-runtime
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Download artifact
+      uses: actions/download-artifact@master
+      with:
+        name: libpgf-ubuntu
+    - run: |
+        sudo mv lib/* /usr/local/lib/
+        sudo mv include/* /usr/local/include/
+
+    - name: Install bindings
       working-directory: ./src/runtime/python
       run: |
         python setup.py build
         sudo python setup.py install
 
-    - name: Run Python testsuite
+    - name: Run testsuite
       working-directory: ./src/runtime/python
-      env:
-        LD_LIBRARY_PATH: /usr/local/lib
       run: |
         pip install pytest
         pytest
 
-    - name: Run JavaScript testsuite
+  ubuntu-javascript:
+    name: JavaScript (Ubuntu)
+    runs-on: ubuntu-20.04
+    needs: ubuntu-runtime
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Download artifact
+      uses: actions/download-artifact@master
+      with:
+        name: libpgf-ubuntu
+    - run: |
+        sudo mv lib/* /usr/local/lib/
+        sudo mv include/* /usr/local/include/
+
+    - name: Install dependencies
       working-directory: ./src/runtime/javascript
-      env:
-        LD_LIBRARY_PATH: /usr/local/lib
       run: |
         npm ci
+
+    - name: Run testsuite
+      working-directory: ./src/runtime/javascript
+      run: |
         npm run test
+
+# ----------------------------------------------------------------------------
+
+  macos-runtime:
+    name: Runtime (macOS)
+    runs-on: macOS-11
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install build tools
+      run: |
+        brew install \
+          autoconf \
+          automake \
+          libtool \
+
+    - name: Build runtime
+      working-directory: ./src/runtime/c
+      run: |
+        glibtoolize
+        autoreconf -i
+        ./configure
+        make
+        sudo make install
+
+    - name: Upload artifact
+      uses: actions/upload-artifact@master
+      with:
+        name: libpgf-macos
+        path: |
+          /usr/local/lib/libpgf*
+          /usr/local/include/pgf
+
+  macos-haskell:
+    name: Haskell (macOS)
+    runs-on: macOS-11
+    needs: macos-runtime
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Download artifact
+      uses: actions/download-artifact@master
+      with:
+        name: libpgf-macos
+    - run: |
+        sudo mv lib/* /usr/local/lib/
+        sudo mv include/* /usr/local/include/
+
+    - name: Setup Haskell
+      uses: haskell/actions/setup@v1
+
+    - name: Build & run testsuite
+      working-directory: ./src/runtime/haskell
+      run: |
+        cabal test --extra-lib-dirs=/usr/local/lib
diff --git a/src/runtime/c/README.md b/src/runtime/c/README.md
index 011ba33a3..43f394891 100644
--- a/src/runtime/c/README.md
+++ b/src/runtime/c/README.md
@@ -17,18 +17,47 @@ g++
 
 - Install XCode from App Store
 - Install XCode command line tools: `xcode-select --install`
+- Required system packages (`brew install ...`):
+```
+autoconf
+automake
+libtool
+```
 
 ## Installation
 
-Installing the runtime (puts libraries in `/usr/local/lib`):
+**Note for macOS**: you should first run `glibtoolize`, followed by the commands below.
+
 ```
 autoreconf -i
 ./configure
 make
 make install
 ```
+The shared libraries are installed in `/usr/local/lib`.
 
 ## Using
 
 - Compiling GF with this runtime will require flag `--extra-lib-dirs=/usr/local/lib`.
 - Running GF with this runtime will require environment variable `LD_LIBRARY_PATH=/usr/local/lib`
+
+## Uninstalling
+
+To remove the _old_ C runtime from your system, do:
+```
+rm /usr/local/lib/libpgf.*
+rm /usr/local/lib/libgu.*
+rm /usr/local/lib/libsg.*
+rm -rf /usr/local/include/pgf
+```
+
+To remove _this_ version of the runtime from your system, do:
+```
+rm /usr/local/lib/libpgf.*
+rm -rf /usr/local/include/pgf
+```
+
+To clean all generated build files from this directory, use:
+```
+git clean -Xdf  
+```