I'm looking for an diagram tool for producing diagrams from text. I only really need sequence and state type diagrams for now, but I'm curious as to what people would recommend? I need something which is standalone, not a web based tool that works on Linux, OSX and Windows.
I'm not positive what you mean by "producing diagrams from text", but if you mean a tool where diagrams are specified by a text file, Graphviz is good. If you mean something that literally converts ascii art like
+--------+ +-------+ +-------+
| | --+ ditaa +--> | |
| Text | +-------+ |diagram|
|Document| |!magic!| | |
| {d}| | | | |
+---+----+ +-------+ +-------+
: ^
| Lots of work |
+-------------------------+
to a graphic:
You can try ditaa (that ascii art is from their website, so it's a good example of the input format it expects)