External renderers for blender

Here is a list of free renderers which are compatible with Blender.

http://www.toxicengine.org/ - "toxic is a physically correct global illumination renderer" its for photrealistic rendering. but still, handy to know about.

http://www.aqsis.org/xoops/modules/news/ - A renderman compliant renderer.
I've downloaded this, I will play with NPR shaders with it sometime.

http://sunflow.sourceforge.net/ - another photrealistic renderer, this time in Java.

http://www.pointzero.nl/renderers/ - a list of renderers, I think it has ones for Blender on it as well.

http://shell.studenti.unina.it/~ospite/vrm/section/en/about.html - more of a plugin for Blender, I think. Its a vector graphic renderer.

Yafray (www.yafray.org) is a realistic rendering engine for Blender as well.

a free addon for Blender is: http://www3.sympatico.ca/emilio.aguirre/s2flender.html flender, a blender to flash (swf) converter. Latest version is 2.6, I used an older version, and it was pretty sweet.

blend 2 sketch, a pretty awesome looking converter which exports to Sketch (vector images) http://www.fauskes.net/code/blend2sketch/
Sketch manual:
http://www.frontiernet.net/~eugene.ressler/manual.html

Comics style rendering engine thing. This generates images with really hard blacks, which look like they come out of an old school comic book (like 2000 AD or something). Its quite nice looking, but a hard style to get right.
http://inkulator.sourceforge.net/index.php