I just saw that Leveller, a heightfield/bumpmap/terrain modeler, needs funds to go open source.
I tried the demo some years ago and quite liked it. Open sourcing it would eventually give Linux users (and maybe others) a terrain modeler that is at the moment lacking on this os (aside from things like Blender plugins, of course 
).
So, if anybody is interested to donate for this cause, I thought I’d mention it here.
Sanne