Ask HN: Software for diagramming a system?

It is OS X only, not open source, and I haven't used it myself, but I've heard a lot of recommendations for OmniGraffle.

http://www.omnigroup.com/applications/omnigraffle/

I was in the market for just such a beast a couple of years back: open source, high quality, cross platform. I'm not sure it exists yet.

That does look nice. Thanks!

FWIW, OmniGraffle is the commercial solution on the Mac that pretty much everybody uses. If you're going to be doing diagrams more than every great once in awhile, it's worth investing in something good.

I've been using it for years and it's what I do all of my hand created diagrams in.

Another alternative is Dia: http://live.gnome.org/Dia

It is (or was last I looked) less polished than OmniGraffle, but open source and cross-platform.