Can any one recommend a free open source diagram editor which supports state machine documentation and editing?

The Moore Machine or the Mealy Machine styles are preferred but not critical.

(as shown at Wikipedia)

http://en.wikipedia.org/wiki/State_diagram

Thanks!

Dia and UMLet.

Dia would be the most logical choice.
I often draw those in Inkscape. Inkscape is a versatile tool and can do anything when it comes to vector drawing. The price you have to pay is that you have to draw the primitives yourself.
If you are willing to spend a few months struggling against a steep learning curve: Tikz. That is a Latex library. You have never seen more beautifully documented state machines.
http://www.google.com/url?sa=t&rct=j...xLmTHFUFfw042Q


jlinkels

I quite like GraphViz for state machines. Kinda does all the work for you, just need to declare what nodes and connections there are.

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Impressive, it seems that GraphViz was just made for that.

jlinkels

I ran across finomaton at some point, although I never actually got around to using it...

Pencil.

Paper.

Seriously...

Thanks for your suggetions. Here is my evaluation if you are interested:

Dia was is easy to use and supports the style I am looking for.

UMLet is also very easy to use but the state transitions are always straight lines and the transition labels are always on top of the lines. This is hard to read and makes large state machines difficult to interpret.

Tikz was not investigated.

GraphViz is amazing! It has lots of applications. It did quite well with a simple state machine until the state names and the transition labels got more than a couple of characters long. Then the automatic layout stumbled badly and produced some very bizzare drawings. Note that this was with the same SM but with more detail in the names.

Finomation looked promising but I couldn't figure out how to use it at all. I could not find a help file.

Pencil and Paper (and Eraser) are clearly the best place to start with the tools we have today.

It is definitely nice that you tried most of the recommendations and provided feedback on them. Thanks for that.

If I assume correctly Finomation is some sort of Latex macro package. Had you been able to speak Latex, you might have understood the package as well.

I assume you are not writing in Latex, so the Latex packages would not be suitable. If you ever decide to write your documents in Latex, XY-pic (http://www.tug.org/applications/Xy-pic/) is yet another state transition drawing package. However, XY-pic is considered to be superseeded by Tikz which offers an order of magnitude commands more. (Ten times more commands is exactly most beginners in Latex are just waiting for isn't it? )

Latex produces the most beautifully typeset documents. If you are able to write your state diagrams and figures in Latex commands, you are assured of matching fonts both in type and size. When you distribute the document as source, you are never confronted with incompatible picture formats, or pictures which are forgotten or out-of-date in your zip or tar file.

It takes only about 3 months studying to get your Latex documents right, and another 6 months for the graphics part, but then you master something real useful.

jlinkels

Actually:
It is a graphical editor.

The tarball contains a README

I stand corrected.

jlinkels