If you can help or wish to become one of the maintainers - just start helping. You can find more RVM related projects at RVM Github organization.
RVM customizes the irb prompt to display the current ruby. You can extend and/or override the prompt setting (see IRB's documentation) in your ~/.irbrc.
For example, to switch back to all Ruby's default behavior add the following line to your ~/.irbrc file:
IRB.conf[:PROMPT_MODE] = :DEFAULT
- You can read all about IRB at ruby-doc.org