The PVM patch for POV-Ray gives POV the ability to distribute a rendering across multiple heterogeneous systems. Using the PVM code, there is one master and many slave tasks. The master has the responsibility of dividing the image up into small blocks, which are assigned to the slaves. When the slaves have finished rendering the blocks, they are sent back to the master, which combines them to form the final image.

Have a look into the PVMPOV-HOWTO.

There is an unstable version of the PVM patch for POV-Ray 3.5:

..as well as there are older, more stable PVM patches for POV-Ray 3.1:

	These patches only work with the unix sources of POV-Ray.

Known bugs can be found here.

As with any unofficial modification to POV-Ray, the PVMPOV Team is not responsible for this code. The standard disclaimer applies:

"The author disclaims all warranties with regard to this software, including all implied warranties of merchant-ability and fitness. The code is simply distributed as it is. The code may be distributed under the same conditions as apply to the POV-Ray source code. These conditions can be found in the file POVLEGAL.DOC, which should be distributed with the POV-Ray code."