> Also, aren't there possible incompatibilities between ruby 1.9.x and ruby 2.0.0?

Yes they are but AFAIK, apart from the new features, these incompatibilities just concern the Ruby code (e.g. String#chars returns an Array in 2.0 but returns an Enumerator in 1.9.3). Redcarpet is (mostly) written in C and I don't think 2.0 change anything from its API (at least nothing we are currently using in Redcarpet's code).

>  If the code base supports both, I think RVM should be mandated to run the unit tests in both ruby 1.9.2 and/or 1.9.3 and ruby 2.0.0.

This is still the case. Please see the [.travis.yml](https://github.com/vmg/redcarpet/blob/master/.travis.yml#L1) file. :smiley: