tmesh is meant to be an extensible platform, meaning that it should be good enough to run any machine description coded according to its standards. The standards have yet to be documented outside of the source code. Right now, the only guest machines available are sun2, sun3, sun4c, and sun4u (ultra-1). These work reasonably well right now, but stability improvements are an ongoing affair. They are meant for demonstration purposes alone, but will run relatively complete emulations of certain configurations as documented on the original TME site.
Some guest operating systems have been tested as well. We will try to document these as we test things out further. It is known that both NetBSD & OpenBSD (latest versions) are known to work pretty well on all the guest machines. In addition, ethernet configuration has been one of the major points of effort in this latest version of TME (the other being upgrading from GTK+2 to GTK+3).