I don't think there's a publicly available playable version.
Who cares then? It's like talking about Kaduria and wondering what kind of combat system it has. What is the point?
For Kaduria, sure. For tcod, a number of reasons could be listed, like historical interest, learning from past design experiments, etc. How
is the combat system in Kaduria, by the way?
As always,
Minotauros
PS. For what it's worth, I never played tcod, but remember it always looked very pretty in screen shots, especially the generated worlds.