Main author here of the library: I just released the 4th major version of BehaviorTree.CPP.<p><a href="https://github.com/BehaviorTree/BehaviorTree.CPP" rel="nofollow">https://github.com/BehaviorTree/BehaviorTree.CPP</a><p>This library is increasingly popular in robotics and automation, and I am very excited about the new features being introduced.