Model Train Design with XTrkCad
One cool program that caught my eye is XTrkCad. It won't appeal to everyone, but for any model train enthusiasts out there it might be just the thing you need to design your next track.
XTrkCad is available from both the Debian and Ubuntu repositories and uses a Gtk graphical interface. At its heart, XTrkCad is a CAD (Computer Aided Design) program, but it was created with model railroad layouts in mind.
In addition to simple track layout, you can also simulate cars and engines to make sure that clearances are accurate and to ensure the switching happens when needed so trains don't plow into each other.
I won't go through the full feature list, since that is available on the website, but suffice to say that is is extensive. XTrkCad has been around since the mid-90's, so it has had plenty of time to get it right.
If you have been thinking about putting a model train setup together then XTrkCad may be just what you were looking for.