diff --git a/README.md b/README.md
index 5bd8bd9..d8c9c09 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,12 @@
 Go by Example book source.
 
 
+### Building Tools
+
+```console
+$ tool/build
+```
+
 ### Numbering
 
 ```console
diff --git a/tool/generate b/tool/generate
deleted file mode 100755
index 26b2afe..0000000
--- a/tool/generate
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/bash
-
-mkdir -p build
-cp style/book.css build/book.css
diff --git a/tool/generate.go b/tool/generate.go
new file mode 100644
index 0000000..bbf10e5
--- /dev/null
+++ b/tool/generate.go
@@ -0,0 +1,30 @@
+package main
+
+import (
+    "os"
+    "os/exec"
+    "fmt"
+)
+
+func check(err error) {
+    if err != nil {
+        panic(err)
+    }
+}
+
+func main() {
+    var err error
+
+    // Accept exactly 1 argument - the input filename.
+    if len(os.Args) != 2 {
+        fmt.Fprintln(os.Stderr, "Usage: tool/generate input.go > output.html")
+        os.Exit(1)
+    }
+
+    // Ensure that we have `markdown` and `pygmentize` binaries.
+    markdownPath, err := exec.LookPath("markdown"); 
+    check(err)
+    pygmentizePath, err := exec.LookPath("pygmentize")
+    check(err)
+    fmt.Println(markdownPath, pygmentizePath)
+}
diff --git a/tool/number b/tool/number
deleted file mode 100755
index 2f5e599..0000000
--- a/tool/number
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-exec go run tool/renumber.go