A better A* algorithm
A few years ago I needed a path finding algorithm in a hurry for a procedural level generator I was trying to write. I managed to find a C# one that supported a number of options and was focused on performance. I reached out to the author if they minded if I changed it a bit and package it up as a nuget. The author agreed, and I used the library in a couple procedural level generators such as Promethean.