diff --git a/overlay.nix b/overlay.nix
index beeec3e..f731211 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -6,6 +6,9 @@ let
   override = rec {
     # These packages will hide packages in the top level nixpkgs
     swift = self.callPackage ./pkgs/swift { };
+
+    # Add our additional node packages
+    nodePackages = super.nodePackages // self.callPackage ./pkgs/node-packages { };
   };
 in {
   replitPackages = rec {
diff --git a/pkgs/node-packages/default.nix b/pkgs/node-packages/default.nix
new file mode 100644
index 0000000..23ba53c
--- /dev/null
+++ b/pkgs/node-packages/default.nix
@@ -0,0 +1,20 @@
+# This file has been generated by node2nix 1.9.0. Do not edit!
+
+{ pkgs ? import <nixpkgs> {
+    inherit system;
+  }
+, system ? builtins.currentSystem
+, nodejs ? pkgs."nodejs-12_x"
+}:
+
+let
+  nodeEnv = import ./node-env.nix {
+    inherit (pkgs) stdenv lib python2 runCommand writeTextFile;
+    inherit pkgs nodejs;
+    libtool = if pkgs.stdenv.isDarwin then pkgs.darwin.cctools else null;
+  };
+in
+import ./node-packages.nix {
+  inherit (pkgs) fetchurl nix-gitignore stdenv lib fetchgit;
+  inherit nodeEnv;
+}
diff --git a/pkgs/node-packages/generate.sh b/pkgs/node-packages/generate.sh
new file mode 100755
index 0000000..fb6dea5
--- /dev/null
+++ b/pkgs/node-packages/generate.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+nix-shell -p nodePackages.node2nix --run 'node2nix -i node-packages.json'
+nix-shell -p nixpkgs-fmt --run 'nixpkgs-fmt .'
+
diff --git a/pkgs/node-packages/node-env.nix b/pkgs/node-packages/node-env.nix
new file mode 100644
index 0000000..9bb0331
--- /dev/null
+++ b/pkgs/node-packages/node-env.nix
@@ -0,0 +1,572 @@
+# This file originates from node2nix
+
+{ lib, stdenv, nodejs, python2, pkgs, libtool, runCommand, writeTextFile }:
+
+let
+  # Workaround to cope with utillinux in Nixpkgs 20.09 and util-linux in Nixpkgs master
+  utillinux = if pkgs ? utillinux then pkgs.utillinux else pkgs.util-linux;
+
+  python = if nodejs ? python then nodejs.python else python2;
+
+  # Create a tar wrapper that filters all the 'Ignoring unknown extended header keyword' noise
+  tarWrapper = runCommand "tarWrapper" { } ''
+    mkdir -p $out/bin
+
+    cat > $out/bin/tar <<EOF
+    #! ${stdenv.shell} -e
+    $(type -p tar) "\$@" --warning=no-unknown-keyword --delay-directory-restore
+    EOF
+
+    chmod +x $out/bin/tar
+  '';
+
+  # Function that generates a TGZ file from a NPM project
+  buildNodeSourceDist =
+    { name, version, src, ... }:
+
+    stdenv.mkDerivation {
+      name = "node-tarball-${name}-${version}";
+      inherit src;
+      buildInputs = [ nodejs ];
+      buildPhase = ''
+        export HOME=$TMPDIR
+        tgzFile=$(npm pack | tail -n 1) # Hooks to the pack command will add output (https://docs.npmjs.com/misc/scripts)
+      '';
+      installPhase = ''
+        mkdir -p $out/tarballs
+        mv $tgzFile $out/tarballs
+        mkdir -p $out/nix-support
+        echo "file source-dist $out/tarballs/$tgzFile" >> $out/nix-support/hydra-build-products
+      '';
+    };
+
+  includeDependencies = { dependencies }:
+    lib.optionalString (dependencies != [ ])
+      (lib.concatMapStrings
+        (dependency:
+          ''
+            # Bundle the dependencies of the package
+            mkdir -p node_modules
+            cd node_modules
+
+            # Only include dependencies if they don't exist. They may also be bundled in the package.
+            if [ ! -e "${dependency.name}" ]
+            then
+                ${composePackage dependency}
+            fi
+
+            cd ..
+          ''
+        )
+        dependencies);
+
+  # Recursively composes the dependencies of a package
+  composePackage = { name, packageName, src, dependencies ? [ ], ... }@args:
+    builtins.addErrorContext "while evaluating node package '${packageName}'" ''
+      DIR=$(pwd)
+      cd $TMPDIR
+
+      unpackFile ${src}
+
+      # Make the base dir in which the target dependency resides first
+      mkdir -p "$(dirname "$DIR/${packageName}")"
+
+      if [ -f "${src}" ]
+      then
+          # Figure out what directory has been unpacked
+          packageDir="$(find . -maxdepth 1 -type d | tail -1)"
+
+          # Restore write permissions to make building work
+          find "$packageDir" -type d -exec chmod u+x {} \;
+          chmod -R u+w "$packageDir"
+
+          # Move the extracted tarball into the output folder
+          mv "$packageDir" "$DIR/${packageName}"
+      elif [ -d "${src}" ]
+      then
+          # Get a stripped name (without hash) of the source directory.
+          # On old nixpkgs it's already set internally.
+          if [ -z "$strippedName" ]
+          then
+              strippedName="$(stripHash ${src})"
+          fi
+
+          # Restore write permissions to make building work
+          chmod -R u+w "$strippedName"
+
+          # Move the extracted directory into the output folder
+          mv "$strippedName" "$DIR/${packageName}"
+      fi
+
+      # Unset the stripped name to not confuse the next unpack step
+      unset strippedName
+
+      # Include the dependencies of the package
+      cd "$DIR/${packageName}"
+      ${includeDependencies { inherit dependencies; }}
+      cd ..
+      ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+    '';
+
+  pinpointDependencies = { dependencies, production }:
+    let
+      pinpointDependenciesFromPackageJSON = writeTextFile {
+        name = "pinpointDependencies.js";
+        text = ''
+          var fs = require('fs');
+          var path = require('path');
+
+          function resolveDependencyVersion(location, name) {
+              if(location == process.env['NIX_STORE']) {
+                  return null;
+              } else {
+                  var dependencyPackageJSON = path.join(location, "node_modules", name, "package.json");
+
+                  if(fs.existsSync(dependencyPackageJSON)) {
+                      var dependencyPackageObj = JSON.parse(fs.readFileSync(dependencyPackageJSON));
+
+                      if(dependencyPackageObj.name == name) {
+                          return dependencyPackageObj.version;
+                      }
+                  } else {
+                      return resolveDependencyVersion(path.resolve(location, ".."), name);
+                  }
+              }
+          }
+
+          function replaceDependencies(dependencies) {
+              if(typeof dependencies == "object" && dependencies !== null) {
+                  for(var dependency in dependencies) {
+                      var resolvedVersion = resolveDependencyVersion(process.cwd(), dependency);
+
+                      if(resolvedVersion === null) {
+                          process.stderr.write("WARNING: cannot pinpoint dependency: "+dependency+", context: "+process.cwd()+"\n");
+                      } else {
+                          dependencies[dependency] = resolvedVersion;
+                      }
+                  }
+              }
+          }
+
+          /* Read the package.json configuration */
+          var packageObj = JSON.parse(fs.readFileSync('./package.json'));
+
+          /* Pinpoint all dependencies */
+          replaceDependencies(packageObj.dependencies);
+          if(process.argv[2] == "development") {
+              replaceDependencies(packageObj.devDependencies);
+          }
+          replaceDependencies(packageObj.optionalDependencies);
+
+          /* Write the fixed package.json file */
+          fs.writeFileSync("package.json", JSON.stringify(packageObj, null, 2));
+        '';
+      };
+    in
+    ''
+      node ${pinpointDependenciesFromPackageJSON} ${if production then "production" else "development"}
+
+      ${lib.optionalString (dependencies != [])
+        ''
+          if [ -d node_modules ]
+          then
+              cd node_modules
+              ${lib.concatMapStrings (dependency: pinpointDependenciesOfPackage dependency) dependencies}
+              cd ..
+          fi
+        ''}
+    '';
+
+  # Recursively traverses all dependencies of a package and pinpoints all
+  # dependencies in the package.json file to the versions that are actually
+  # being used.
+
+  pinpointDependenciesOfPackage = { packageName, dependencies ? [ ], production ? true, ... }@args:
+    ''
+      if [ -d "${packageName}" ]
+      then
+          cd "${packageName}"
+          ${pinpointDependencies { inherit dependencies production; }}
+          cd ..
+          ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+      fi
+    '';
+
+  # Extract the Node.js source code which is used to compile packages with
+  # native bindings
+  nodeSources = runCommand "node-sources" { } ''
+    tar --no-same-owner --no-same-permissions -xf ${nodejs.src}
+    mv node-* $out
+  '';
+
+  # Script that adds _integrity fields to all package.json files to prevent NPM from consulting the cache (that is empty)
+  addIntegrityFieldsScript = writeTextFile {
+    name = "addintegrityfields.js";
+    text = ''
+      var fs = require('fs');
+      var path = require('path');
+
+      function augmentDependencies(baseDir, dependencies) {
+          for(var dependencyName in dependencies) {
+              var dependency = dependencies[dependencyName];
+
+              // Open package.json and augment metadata fields
+              var packageJSONDir = path.join(baseDir, "node_modules", dependencyName);
+              var packageJSONPath = path.join(packageJSONDir, "package.json");
+
+              if(fs.existsSync(packageJSONPath)) { // Only augment packages that exist. Sometimes we may have production installs in which development dependencies can be ignored
+                  console.log("Adding metadata fields to: "+packageJSONPath);
+                  var packageObj = JSON.parse(fs.readFileSync(packageJSONPath));
+
+                  if(dependency.integrity) {
+                      packageObj["_integrity"] = dependency.integrity;
+                  } else {
+                      packageObj["_integrity"] = "sha1-000000000000000000000000000="; // When no _integrity string has been provided (e.g. by Git dependencies), add a dummy one. It does not seem to harm and it bypasses downloads.
+                  }
+
+                  if(dependency.resolved) {
+                      packageObj["_resolved"] = dependency.resolved; // Adopt the resolved property if one has been provided
+                  } else {
+                      packageObj["_resolved"] = dependency.version; // Set the resolved version to the version identifier. This prevents NPM from cloning Git repositories.
+                  }
+
+                  if(dependency.from !== undefined) { // Adopt from property if one has been provided
+                      packageObj["_from"] = dependency.from;
+                  }
+
+                  fs.writeFileSync(packageJSONPath, JSON.stringify(packageObj, null, 2));
+              }
+
+              // Augment transitive dependencies
+              if(dependency.dependencies !== undefined) {
+                  augmentDependencies(packageJSONDir, dependency.dependencies);
+              }
+          }
+      }
+
+      if(fs.existsSync("./package-lock.json")) {
+          var packageLock = JSON.parse(fs.readFileSync("./package-lock.json"));
+
+          if(![1, 2].includes(packageLock.lockfileVersion)) {
+             process.stderr.write("Sorry, I only understand lock file versions 1 and 2!\n");
+             process.exit(1);
+          }
+
+          if(packageLock.dependencies !== undefined) {
+              augmentDependencies(".", packageLock.dependencies);
+          }
+      }
+    '';
+  };
+
+  # Reconstructs a package-lock file from the node_modules/ folder structure and package.json files with dummy sha1 hashes
+  reconstructPackageLock = writeTextFile {
+    name = "addintegrityfields.js";
+    text = ''
+      var fs = require('fs');
+      var path = require('path');
+
+      var packageObj = JSON.parse(fs.readFileSync("package.json"));
+
+      var lockObj = {
+          name: packageObj.name,
+          version: packageObj.version,
+          lockfileVersion: 1,
+          requires: true,
+          dependencies: {}
+      };
+
+      function augmentPackageJSON(filePath, dependencies) {
+          var packageJSON = path.join(filePath, "package.json");
+          if(fs.existsSync(packageJSON)) {
+              var packageObj = JSON.parse(fs.readFileSync(packageJSON));
+              dependencies[packageObj.name] = {
+                  version: packageObj.version,
+                  integrity: "sha1-000000000000000000000000000=",
+                  dependencies: {}
+              };
+              processDependencies(path.join(filePath, "node_modules"), dependencies[packageObj.name].dependencies);
+          }
+      }
+
+      function processDependencies(dir, dependencies) {
+          if(fs.existsSync(dir)) {
+              var files = fs.readdirSync(dir);
+
+              files.forEach(function(entry) {
+                  var filePath = path.join(dir, entry);
+                  var stats = fs.statSync(filePath);
+
+                  if(stats.isDirectory()) {
+                      if(entry.substr(0, 1) == "@") {
+                          // When we encounter a namespace folder, augment all packages belonging to the scope
+                          var pkgFiles = fs.readdirSync(filePath);
+
+                          pkgFiles.forEach(function(entry) {
+                              if(stats.isDirectory()) {
+                                  var pkgFilePath = path.join(filePath, entry);
+                                  augmentPackageJSON(pkgFilePath, dependencies);
+                              }
+                          });
+                      } else {
+                          augmentPackageJSON(filePath, dependencies);
+                      }
+                  }
+              });
+          }
+      }
+
+      processDependencies("node_modules", lockObj.dependencies);
+
+      fs.writeFileSync("package-lock.json", JSON.stringify(lockObj, null, 2));
+    '';
+  };
+
+  prepareAndInvokeNPM = { packageName, bypassCache, reconstructLock, npmFlags, production }:
+    let
+      forceOfflineFlag = if bypassCache then "--offline" else "--registry http://www.example.com";
+    in
+    ''
+      # Pinpoint the versions of all dependencies to the ones that are actually being used
+      echo "pinpointing versions of dependencies..."
+      source $pinpointDependenciesScriptPath
+
+      # Patch the shebangs of the bundled modules to prevent them from
+      # calling executables outside the Nix store as much as possible
+      patchShebangs .
+
+      # Deploy the Node.js package by running npm install. Since the
+      # dependencies have been provided already by ourselves, it should not
+      # attempt to install them again, which is good, because we want to make
+      # it Nix's responsibility. If it needs to install any dependencies
+      # anyway (e.g. because the dependency parameters are
+      # incomplete/incorrect), it fails.
+      #
+      # The other responsibilities of NPM are kept -- version checks, build
+      # steps, postprocessing etc.
+
+      export HOME=$TMPDIR
+      cd "${packageName}"
+      runHook preRebuild
+
+      ${lib.optionalString bypassCache ''
+        ${lib.optionalString reconstructLock ''
+          if [ -f package-lock.json ]
+          then
+              echo "WARNING: Reconstruct lock option enabled, but a lock file already exists!"
+              echo "This will most likely result in version mismatches! We will remove the lock file and regenerate it!"
+              rm package-lock.json
+          else
+              echo "No package-lock.json file found, reconstructing..."
+          fi
+
+          node ${reconstructPackageLock}
+        ''}
+
+        node ${addIntegrityFieldsScript}
+      ''}
+
+      npm ${forceOfflineFlag} --nodedir=${nodeSources} ${npmFlags} ${lib.optionalString production "--production"} rebuild
+
+      if [ "''${dontNpmInstall-}" != "1" ]
+      then
+          # NPM tries to download packages even when they already exist if npm-shrinkwrap is used.
+          rm -f npm-shrinkwrap.json
+
+          npm ${forceOfflineFlag} --nodedir=${nodeSources} ${npmFlags} ${lib.optionalString production "--production"} install
+      fi
+    '';
+
+  # Builds and composes an NPM package including all its dependencies
+  buildNodePackage =
+    { name
+    , packageName
+    , version
+    , dependencies ? [ ]
+    , buildInputs ? [ ]
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , preRebuild ? ""
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ...
+    }@args:
+
+    let
+      extraArgs = removeAttrs args [ "name" "dependencies" "buildInputs" "dontStrip" "dontNpmInstall" "preRebuild" "unpackPhase" "buildPhase" ];
+    in
+    stdenv.mkDerivation ({
+      name = "node_${name}-${version}";
+      buildInputs = [ tarWrapper python nodejs ]
+        ++ lib.optional (stdenv.isLinux) utillinux
+        ++ lib.optional (stdenv.isDarwin) libtool
+        ++ buildInputs;
+
+      inherit nodejs;
+
+      inherit dontStrip; # Stripping may fail a build for some package deployments
+      inherit dontNpmInstall preRebuild unpackPhase buildPhase;
+
+      compositionScript = composePackage args;
+      pinpointDependenciesScript = pinpointDependenciesOfPackage args;
+
+      passAsFile = [ "compositionScript" "pinpointDependenciesScript" ];
+
+      installPhase = ''
+        # Create and enter a root node_modules/ folder
+        mkdir -p $out/lib/node_modules
+        cd $out/lib/node_modules
+
+        # Compose the package and all its dependencies
+        source $compositionScriptPath
+
+        ${prepareAndInvokeNPM { inherit packageName bypassCache reconstructLock npmFlags production; }}
+
+        # Create symlink to the deployed executable folder, if applicable
+        if [ -d "$out/lib/node_modules/.bin" ]
+        then
+            ln -s $out/lib/node_modules/.bin $out/bin
+        fi
+
+        # Create symlinks to the deployed manual page folders, if applicable
+        if [ -d "$out/lib/node_modules/${packageName}/man" ]
+        then
+            mkdir -p $out/share
+            for dir in "$out/lib/node_modules/${packageName}/man/"*
+            do
+                mkdir -p $out/share/man/$(basename "$dir")
+                for page in "$dir"/*
+                do
+                    ln -s $page $out/share/man/$(basename "$dir")
+                done
+            done
+        fi
+
+        # Run post install hook, if provided
+        runHook postInstall
+      '';
+    } // extraArgs);
+
+  # Builds a node environment (a node_modules folder and a set of binaries)
+  buildNodeDependencies =
+    { name
+    , packageName
+    , version
+    , src
+    , dependencies ? [ ]
+    , buildInputs ? [ ]
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ...
+    }@args:
+
+    let
+      extraArgs = removeAttrs args [ "name" "dependencies" "buildInputs" ];
+    in
+    stdenv.mkDerivation ({
+      name = "node-dependencies-${name}-${version}";
+
+      buildInputs = [ tarWrapper python nodejs ]
+        ++ lib.optional (stdenv.isLinux) utillinux
+        ++ lib.optional (stdenv.isDarwin) libtool
+        ++ buildInputs;
+
+      inherit dontStrip; # Stripping may fail a build for some package deployments
+      inherit dontNpmInstall unpackPhase buildPhase;
+
+      includeScript = includeDependencies { inherit dependencies; };
+      pinpointDependenciesScript = pinpointDependenciesOfPackage args;
+
+      passAsFile = [ "includeScript" "pinpointDependenciesScript" ];
+
+      installPhase = ''
+        mkdir -p $out/${packageName}
+        cd $out/${packageName}
+
+        source $includeScriptPath
+
+        # Create fake package.json to make the npm commands work properly
+        cp ${src}/package.json .
+        chmod 644 package.json
+        ${lib.optionalString bypassCache ''
+          if [ -f ${src}/package-lock.json ]
+          then
+              cp ${src}/package-lock.json .
+          fi
+        ''}
+
+        # Go to the parent folder to make sure that all packages are pinpointed
+        cd ..
+        ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+
+        ${prepareAndInvokeNPM { inherit packageName bypassCache reconstructLock npmFlags production; }}
+
+        # Expose the executables that were installed
+        cd ..
+        ${lib.optionalString (builtins.substring 0 1 packageName == "@") "cd .."}
+
+        mv ${packageName} lib
+        ln -s $out/lib/node_modules/.bin $out/bin
+      '';
+    } // extraArgs);
+
+  # Builds a development shell
+  buildNodeShell =
+    { name
+    , packageName
+    , version
+    , src
+    , dependencies ? [ ]
+    , buildInputs ? [ ]
+    , production ? true
+    , npmFlags ? ""
+    , dontNpmInstall ? false
+    , bypassCache ? false
+    , reconstructLock ? false
+    , dontStrip ? true
+    , unpackPhase ? "true"
+    , buildPhase ? "true"
+    , ...
+    }@args:
+
+    let
+      nodeDependencies = buildNodeDependencies args;
+    in
+    stdenv.mkDerivation {
+      name = "node-shell-${name}-${version}";
+
+      buildInputs = [ python nodejs ] ++ lib.optional (stdenv.isLinux) utillinux ++ buildInputs;
+      buildCommand = ''
+        mkdir -p $out/bin
+        cat > $out/bin/shell <<EOF
+        #! ${stdenv.shell} -e
+        $shellHook
+        exec ${stdenv.shell}
+        EOF
+        chmod +x $out/bin/shell
+      '';
+
+      # Provide the dependencies in a development shell through the NODE_PATH environment variable
+      inherit nodeDependencies;
+      shellHook = lib.optionalString (dependencies != [ ]) ''
+        export NODE_PATH=${nodeDependencies}/lib/node_modules
+        export PATH="${nodeDependencies}/bin:$PATH"
+      '';
+    };
+in
+{
+  buildNodeSourceDist = lib.makeOverridable buildNodeSourceDist;
+  buildNodePackage = lib.makeOverridable buildNodePackage;
+  buildNodeDependencies = lib.makeOverridable buildNodeDependencies;
+  buildNodeShell = lib.makeOverridable buildNodeShell;
+}
diff --git a/pkgs/node-packages/node-packages.json b/pkgs/node-packages/node-packages.json
new file mode 100644
index 0000000..2e4ef51
--- /dev/null
+++ b/pkgs/node-packages/node-packages.json
@@ -0,0 +1,3 @@
+[
+  "coffeescript"
+]
diff --git a/pkgs/node-packages/node-packages.nix b/pkgs/node-packages/node-packages.nix
new file mode 100644
index 0000000..db1e1a1
--- /dev/null
+++ b/pkgs/node-packages/node-packages.nix
@@ -0,0 +1,27 @@
+# This file has been generated by node2nix 1.9.0. Do not edit!
+
+{ nodeEnv, fetchurl, fetchgit, nix-gitignore, stdenv, lib, globalBuildInputs ? [ ] }:
+
+let
+  sources = { };
+in
+{
+  coffeescript = nodeEnv.buildNodePackage {
+    name = "coffeescript";
+    packageName = "coffeescript";
+    version = "2.6.1";
+    src = fetchurl {
+      url = "https://registry.npmjs.org/coffeescript/-/coffeescript-2.6.1.tgz";
+      sha512 = "GG5nkF93qII8HmHqnnibkgpp/SV7PSnSPiWsbinwya7nNOe95aE/x2xrKZJFks8Qpko3TNrC+/LahaKgrz5YCg==";
+    };
+    buildInputs = globalBuildInputs;
+    meta = {
+      description = "Unfancy JavaScript";
+      homepage = "https://coffeescript.org";
+      license = "MIT";
+    };
+    production = true;
+    bypassCache = true;
+    reconstructLock = true;
+  };
+}
diff --git a/pkgs/node-packages/readme.md b/pkgs/node-packages/readme.md
new file mode 100644
index 0000000..8ca8926
--- /dev/null
+++ b/pkgs/node-packages/readme.md
@@ -0,0 +1,2 @@
+Add additional packages to the node overlay in `node-packages.json`. Build an
+updated package with `./generate`.
diff --git a/shell.nix b/shell.nix
index 0fe77ec..ee521a4 100644
--- a/shell.nix
+++ b/shell.nix
@@ -4,6 +4,7 @@ pkgs.mkShell {
   buildInputs = with pkgs;
     [
       hello
+      nodePackages.coffeescript
 
       # Swift takes a lot of compute to build, it is excluded from CI for now.
       # swift