I liked Together for Java. Before it was bought by Borland, Together was available to academic institutions for free. I used it in my teaching. It had some of the best looking diagrams, could round-trip Java code, and auto-create sequence diagrams. All great stuff when you’re in the business of teaching Modeling and Java to beginning programmers. When Borland bought Together, the free academic licensing deals dissappeared also. Last year I had to rewrite my UML tutorials for Rational Rose (available for free for academic use from IBM) which is far less friendly. In fact most of my students preferred Poseidon Community Edition! Now Borland have released a Community Edition of Together (announced in a news article on the theServerSide.com. I’m downloading it (60 MBytes) now to give it a test drive. It has the usual licensing requirements as JBuilder and Delphi, so it’s a bit awkward for student use (they need an Internet connection to install it), but even if the code syncronization is gone, the diagrams should still be useful.
In the follow-ups to the TSS announcement, violet (already blogged here) was mentioned as were JUDE and OpenSource reverse engineering tool ESS-Model were also mentioned. Both of these will be well worth a look I think, but UMLet (blogged here) still has a lot of appeal for student use (if only it did sequence diagrams!).