Pathfinding?

[Trass3r]

Haven't seen any D code implementing pathfinding yet.

Anyway, A* is dead!
If you plan to code a library choose a proper algo like D* Lite or  
Realtime Adaptive A*:
http://idm-lab.org/project-a.html

For big armies, supreme commander 2's flow field path finding is also  
interesting (based on  
http://grail.cs.washington.edu/projects/crowd-flows/):
http://www.youtube.com/watch?v=jA2epda-RkM