diff --git a/README.md b/README.md
index 6019088..eb0e31d 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,13 @@ emulated in JavaScript.
 - For a description of the peripherals, see the
   [Peripherals](#peripherals) section below.
 
-## Building and Running
+## Building and Running Locally
+
+You'll need:
+
+- [WABT](https://github.com/WebAssembly/wabt)
+- [Guile](https://www.gnu.org/software/guile/) (or bring your own HTTP
+  server -- see note below)
 
 To run, first compile the WebAssembly module: