diff --git a/README.md b/README.md
index 16adc42..683758b 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,28 @@
-# Scratch Everywhere! Extensions
+# Scratch Everywhere! Lua Extensions
 
-A collection of extensions for Scratch Everywhere! including ports of TurboWarp
-extensions.
+A collection of Lua extensions for Scratch Everywhere!, including ports of
+TurboWarp extensions.
 
 > [!WARNING]
 > Custom extensions in Scratch Everywhere! are still in development.
+
+# Building
+
+To build the Lua extensions, use `bun`:
+
+```sh
+bun build.ts
+```
+
+The compiled extensions can be found in the `bin` folder.
+
+Then it should be as simple as copying the `.see` files to
+`scratch-everywhere/extensions` and running Scratch Everywhere!!
+
+# Using in an Editor
+
+`bun` will also build JavaScript versions of the extensions. These are intended
+for use in a Scratch editor that supports loading custom extensions.
+
+> [!NOTE]
+> These extensions will likely not work correctly in the editor.