Recast/Detour (MIT License)

Googlecode link

Recast is a library to generate navigation meshes from polygon soups. Detour is a pathfinding and spatial reasoning toolkit that works on navigation meshes.

OpenSteer (MIT License):

OpenSteer is a C++ library to help construct steering behaviors for autonomous characters in games and animation. In addition to the library, OpenSteer provides an OpenGL-based application called OpenSteerDemo which displays predefined demonstrations of steering behaviors. The user can quickly prototype, visualize, annotate and debug new steering behaviors by writing a plug-in for OpenSteerDemo.

I’ve seen it used to great effect in simple games.

There also MicroPather – an open source path finding library from the same guy who made TinyXML.

http://www.grinninglizard.com/MicroPather/index.htm

Havok AI (Commercial – not cheap)

http://www.havok.com/index.php?page=havok-ai

Havok is pretty good at physics, and has been offering behaviour, animation and other kinds of middleware for a while now.

Physics and AI is not easy to get to cooperate, especially animations, so save yourself some time and use Havok.

Highly recommended. 🙂

If you can afford it.

Pros: Industry strength quality, proven technology. Makes AI and Physics cooperate.

Cons: Steep Price.

AI.implant (Licensed)

http://www.presagis.com/products_services/products/ms/simulation/aiimplant/#

No idea if it’s any good, I just remember getting some brochures from them at GDC a few years back, and it appears they’re still around.

Kynapse (commercial) is from what I understand the number 1 market share for pathfinding libraries. It’s the oldest of the commercial AI middlewares around.

http://usa.autodesk.com/adsk/servlet/pc/index?siteID=123112&id=11390544

My experience with previous versions were that they were bulky with a terrible API and not very nicely implemented. We had tons of problems with it.

Now in their new version it seems they’ve changed data formats and some other radical changes, so maybe they’ve fixed the problems now.

It’s also a commercial product and fairly expensive.

NavPower (commercial)

http://www.babelflux.com/

My experience with it has been positive, although I haven’t shipped any title with it yet. Most others I’ve talked to about it have had a similarly positive experience with it. API is easy to understand.

Fairly simplistic API, which can be a limitation.

Golaem (Commerical)

http://www.golaem.com

I’ll add to the list of commercial products Golaem (Full disclosure: I work for them).

Golaem Path is a real time 3D navigation library (path finding & reactive navigation / steering behaviors). It is not marketed for game development but could be used for a game.

xAItment (commercial)

http://www.xaitment.com/

Fairly new middleware suite providing everything from pathfinding to behavior / decision making systems. Haven’t tried it myself, so I can’t say if it’s any good.

SharpSteer. (MIT license?)

http://sharpsteer.codeplex.com/

SharpSteer is a C# port of OpenSteer. Like OpenSteer, the aim of SharpSteer is to help construct steering behaviors for autonomous characters in games and animation, with a current implementation focus toward Microsoft’s XNA.