phinze/homebrew-cask — pull request #2657 by voanhduy1512 (2014-01-27 10:27:46+00:00)
Title: Implement ideas in #142, multiple versions Cask

Allow for more flexibility with multiple versions of the same app.
Temporate edit firefox.rb for testing only, will revert later. Try

```bash
brew cask install firefox --channel=beta
```

It works now but i think it need more tests. Beside, i implement at minimun size, just to make it work. So any ideas to improve are welcome.