Recs.
Updated
SpecsUpdate
Pros
Pro Added (limited) XMI model import
It now can import a few other tools (very limited, should support any valid XMI model, and it would be nice if it could unpack the awful M$ JET database format used by Enterprise Architect). But, it is a HUGE improvement over when it would just crash if you opened XMI from any other tool.
Pro Code generation
Can generate code for ActionScript, Ada, C++, C#, D, IDL, Java™, JavaScript, MySQL, Pascal, Perl, PHP, PostgreSQL, Python, Ruby, SQL, Tcl, Vala and XMLSchema.
Cons
Con Crashes at awkward moments
Has had problems with stability off and on over the years. It doesn't seem to have much active development, as the UI hasn't changed much in the last decade and certainly could benefit from adopting some more of the UML2 standard than basic class diagrams. Not sure why it needs z-shell to install, but sucked in a ton of Z-shell specific packages.