install_package "yaml-0.1.4" "http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz#36c852831d02cf90508c29852361d01b"
install_package "ruby-1.9.3-p286" "ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p286.tar.gz#e2469b55c2a3d0d643097d47fe4984bb"