Cl2s is a project mainly written in Python, it's free.
Condor Low Latency Scheduling
This is a work in progress: you have been warned!
Condor Low Latency Scheduling (CL2S) Database-based system to execute Condor jobs on a cluster (assumed to be homogeneous) bypassing all match-making negotiations. Makes use of Condor job hooks which run on the compute nodes and fetch jobs directly from a queue. The queue can be anything but it is likely to be a database of some sort.