@ptrefall has shared his Hierarchical Task Network planner project written in C# and drawn from his experience working on Rust's tactical combative AI. Inspired by the Fluid Behavior Tree project, the work references Troy Humphreys GameAIPro article on HTN Planners.
From the topic post:
QuoteIt's based primarily on Troy Humphrey's work, but I also used HTN planning professionally when working on Rust's tactical combative AI in the past. Fluid HTN is a newly written library based on everything I learned using HTN in practice.
My implementation supports partial plans and domain splicing, and is very easy to extend with new decomposition rules, like Random Select or Utility Select.
Check out the project on Github here.