emRPC is an ICE node that renders point clouds directly to disk. Even though the node renders the particles in a rather primitive way it can come in handy when dealing with many particles (>250.000), because it has one great feature: it is fast, so rendering a frame with anti-alias generally only takes a few seconds.
The plug-in consists of a DLL file for the renderer (compiled C++ code for 32 bit and 64 bit versions of XSI) as well as a compound (see following image).
Here you will find the link to the emRenderPointCloud page where you can read a little more about this plug-in, look at some demo animations, download the demo version etc.:
http://www.mootzoid.com/XsiCorner.html#Plugins