diff --git a/packages/modules/.npm/package/.gitignore b/packages/modules/.npm/package/.gitignore
new file mode 100644
index 0000000000..3c3629e647
--- /dev/null
+++ b/packages/modules/.npm/package/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/packages/modules/.npm/package/README b/packages/modules/.npm/package/README
new file mode 100644
index 0000000000..3d492553a4
--- /dev/null
+++ b/packages/modules/.npm/package/README
@@ -0,0 +1,7 @@
+This directory and the files immediately inside it are automatically generated
+when you change this package's NPM dependencies. Commit the files in this
+directory (npm-shrinkwrap.json, .gitignore, and this README) to source control
+so that others run the same versions of sub-dependencies.
+
+You should NOT check in the node_modules directory that Meteor automatically
+creates; if you are using git, the .gitignore file tells git to ignore it.
diff --git a/packages/modules/.npm/package/npm-shrinkwrap.json b/packages/modules/.npm/package/npm-shrinkwrap.json
new file mode 100644
index 0000000000..3d18bb8563
--- /dev/null
+++ b/packages/modules/.npm/package/npm-shrinkwrap.json
@@ -0,0 +1,7 @@
+{
+  "dependencies": {
+    "install": {
+      "version": "0.4.0"
+    }
+  }
+}
diff --git a/packages/modules/README.md b/packages/modules/README.md
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/packages/modules/modules-tests.js b/packages/modules/modules-tests.js
new file mode 100644
index 0000000000..07c400fcaa
--- /dev/null
+++ b/packages/modules/modules-tests.js
@@ -0,0 +1,6 @@
+Tinytest.add('modules', function (test) {
+  test.equal(typeof meteorInstall, "function");
+  var require = meteorInstall();
+  test.equal(typeof require, "function");
+  test.equal(typeof require.ensure, "function");
+});
diff --git a/packages/modules/modules.js b/packages/modules/modules.js
new file mode 100644
index 0000000000..cd1005dca4
--- /dev/null
+++ b/packages/modules/modules.js
@@ -0,0 +1,25 @@
+var options = {};
+
+// RegExp matching strings that don't start with a `.` or a `/`.
+var topLevelIdPattern = /^[^./]/;
+
+// This function will be called whenever a module identifier that hasn't
+// been installed is required. For backwards compatibility, and so that we
+// can require binary dependencies on the server, we implement the
+// fallback in terms of Npm.require.
+options.fallback = function (id, dir, error) {
+  // For simplicity, we honor only top-level module identifiers here.
+  // We could try to honor relative and absolute module identifiers by
+  // somehow combining `id` with `dir`, but we'd have to be really careful
+  // that the resulting modules were located in a known directory (not
+  // some arbitrary location on the file system), and we only really need
+  // the fallback for dependencies installed in node_modules directories.
+  if (topLevelIdPattern.test(id) &&
+      typeof Npm === "object" &&
+      typeof Npm.require === "function") {
+    return Npm.require(id);
+  }
+  throw error;
+};
+
+meteorInstall = makeInstaller(options);
diff --git a/packages/modules/package.js b/packages/modules/package.js
new file mode 100644
index 0000000000..9c45d0700d
--- /dev/null
+++ b/packages/modules/package.js
@@ -0,0 +1,33 @@
+Package.describe({
+  name: "modules",
+  version: "0.4.0",
+  summary: "CommonJS module system",
+  git: "https://github.com/benjamn/install",
+  documentation: "README.md"
+});
+
+Npm.depends({
+  install: "0.4.0"
+});
+
+Package.onUse(function(api) {
+  api.use("meteor", {
+    unordered: true
+  });
+
+  api.addFiles(".npm/package/node_modules/install/install.js", [
+    "client",
+    "server"
+  ], {
+    bare: true
+  });
+
+  api.addFiles("modules.js");
+  api.export("meteorInstall");
+});
+
+Package.onTest(function(api) {
+  api.use("tinytest");
+  api.use("modules");
+  api.addFiles("modules-tests.js");
+});