I'm reworking my own render farm database system for my own needs and will release it at a later date. As my focus is mainly on animations it won't be as useful for cropped renders. I use it mainly to resort the frame order into a progressive render, and spreading this across multiple computers so that a preview of the animation is built up as quickly as possible. It's a fairly low tech apporach but it's realtively effective.
I also incorporate the use of panormama tools for reprojecting the image and creating spherical panoramas on the fly (if required) and any other commandline tools that I end up using (ImageMagick, Arbaro to name a few).
And lastly, CHAN file conversion (e.g. TGS to CHAN) and some basic interpolation of key frames, although once again it will work mainly with existing data and converting it to a form ready for use with TG2. It's not intended to be a universal rendering tool but bits of it may be useful to others.