diff --git a/doc/BUILD_REQUIREMENTS.txt b/doc/BUILD_REQUIREMENTS.txt
index 9afa1e1..0e00e86 100644
--- a/doc/BUILD_REQUIREMENTS.txt
+++ b/doc/BUILD_REQUIREMENTS.txt
@@ -1,2 +1,9 @@
+- ruby
+	http://www.ruby-lang.org/en/downloads/
+	You may also need: [sudo] gem install archive-zip
 - ca65
-- ripxplore.rb >=0.7.0
\ No newline at end of file
+	http://www.cc65.org
+- ripxplore.rb >=0.7.0
+	http://rubyforge.org/frs/?group_id=6922
+	To install: [sudo] gem install ripxplore
+- GNU make or similar