If you're interested in contributing, take a look at where the project is headed in the short-term:

0.7.x releases

• Begin drafting and implementing a plugin API
  • Allow users to implement their own ShellJS commands
  • Add methods on the ShellString class
  • Create commands that have subcommands (of the form git.add('file.txt'))
• Improve the collaboration experience
  • Comments to document confusing parts of the code
  • Implement all commands as internal plugins (almost all changes are in the src file and test file)
• Write simple plugins to dogfood this API
• More unix compatibility with existing commands
• Switch to a standard test framework (to facilitate community contributions)

0.8.x releases

• More secure replacement to shell.exec() (see #524)
  • Try to minimize how much this relies on the file system plugin API (we might release the plugin API before implementing subcommands)
• Don't exit the process for internal failures, throw an exception instead (shell.exit() should be the only part of our API that kills the process)
• Stricter style linting
• Track (and improve) test coverage (goal: 80% line coverage or higher before 0.9)
• Improve performance for commonly used commands

0.9.x releases (if we have these)

• No goals so far

1.x.x releases

• Allow commands to be async (#2)
• Run & publish benchmarks on each version (https://github.com/shelljs/benchmarks)
• Release ShellJS unix commands as separate packages (similar to how cash commands can be installed individually)