Doing my part,
This is my final submission (from Nov 10). Life interfered afterwards and many ideas for improvements went unimplemented. This bot made it to third spot around Thanksgiving and finished the regular season in 13th spot [hoping for top-30 in the finals].
It's a C++ bot with a module for combat (Mini-Max for up to 8 moving ants, and "all-or-nothing" beyond that based on local power balance). It has a food collection strategy as discussed at IRC in the beta time-frame, updated to treat enemy hills as food. Finally, it has exploration code based on a multi-component heuristic score that I found very difficult to tweak properly and became ever more complex (more ingredients) over time. However, this heuristic function is where a lot of strength/weakness appears to come from. I implemented it as a weighted integer sum of distances to a variety of targets (found by BFS). A real value and a distance function would have been the obvious next steps there.
I have made some smallish "improvements" in all of these modules since and integrated visualizer code, but that never consistently resulted in a version that beat this version in local testing. That probably means I introduced some bugs along the way or tweaking the heuristic function became even more fragile. I would need to work on some RL-type of approach there and a better testing strategy, but I did not have the time to work on it. If someone is interested, I would be willing to share that code as well.