diff --git a/stdlib/ktSrc/ModuleBuilder.kt b/stdlib/ktSrc/ModuleBuilder.kt
new file mode 100644
index 00000000000..f6e97a1cdf1
--- /dev/null
+++ b/stdlib/ktSrc/ModuleBuilder.kt
@@ -0,0 +1,47 @@
+namespace kotlin.modules
+
+import java.util.*
+import jet.modules.*
+
+class ModuleSetBuilder() {
+    val modules: ArrayList<ModuleBuilder> = ArrayList<ModuleBuilder>()
+
+    fun module(name: String, callback: fun ModuleBuilder.()) {
+        val builder = ModuleBuilder(name)
+        builder.callback()
+    }
+}
+
+class SourcesBuilder(val parent: ModuleBuilder) {
+    fun files(pattern: String) {
+        parent.addSourceFiles(pattern)
+    }
+}
+
+class ClasspathBuilder(val parent: ModuleBuilder) {
+    fun entry(name: String) {
+        parent.addClasspathEntry(name)
+    }
+}
+
+class ModuleBuilder(val name: String): IModuleBuilder {
+    val sourceFiles: ArrayList<String?> = ArrayList<String?>()
+    val classpathRoots: ArrayList<String?> = ArrayList<String?>()
+
+    val source: SourcesBuilder
+      get() = SourcesBuilder(this)
+
+    val classpath: ClasspathBuilder
+      get() = ClasspathBuilder(this)
+
+    fun addSourceFiles(pattern: String) {
+        sourceFiles.add(pattern)
+    }
+
+    fun addClasspathEntry(name: String) {
+        classpathRoots.add(name)
+    }
+
+    override fun getSourceFiles(): List<String?>? = sourceFiles
+    override fun getClasspathRoots(): List<String?>? = classpathRoots
+}
diff --git a/stdlib/src/jet/modules/IModuleBuilder.java b/stdlib/src/jet/modules/IModuleBuilder.java
new file mode 100644
index 00000000000..53ac51123c6
--- /dev/null
+++ b/stdlib/src/jet/modules/IModuleBuilder.java
@@ -0,0 +1,11 @@
+package jet.modules;
+
+import java.util.List;
+
+/**
+ * @author yole
+ */
+public interface IModuleBuilder {
+    List<String> getSourceFiles();
+    List<String> getClasspathRoots();
+}
diff --git a/stdlib/stdlib.iml b/stdlib/stdlib.iml
index d5c07432750..7140d09842b 100644
--- a/stdlib/stdlib.iml
+++ b/stdlib/stdlib.iml
@@ -4,6 +4,7 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/ktSrc" isTestSource="false" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />