[mark_story]

If a team is using different versions/runtimes of ruby I would have to agree this is an organizational feature in some cases. If you're working on a webapp you should be aiming to make as few differences between a development box & production as possible. Its unlikely that you have jruby & mri in production, wherein lies the failure.

[steveklabnik]

Square is one example of a company which famously develops in MRI but deploys JRuby to production.

[mark_story]

That sounds crazy to me, but I have very little experience with ruby. In PHP/python doing that can be unpleasant.