From ChumbyWiki

Programming languages

• GCC Toolchain (3.3.2, Foo/Katamari alpha prototype chumbys)
  
• GNU Toolchain (4.3.2, Ironforge production chumbys)
  
• Perl
  
• python
  
• ruby
  
• java
  
• lua
  
• squeak
  
• ocaml
  
• Actionscript
  

Other tools

• nano - unpack to USB dongle.