M. Shuaib Khan has published a list of open-source cluster management systems.
Personally, I had used openMosix and Red Hat Cluster software (which is also based upon open source software funded by Red Hat).
From the article: In computing world, the term "cluster" refers to a group of independent computers combined through software and networking, which is often used to run highly compute-intensive jobs. With a cluster, you can build a high-speed supercomputer out of hundreds or even thousands of relatively low-speed systems. Cluster management software offers an easy-to-use interface for managing clusters, and automates the process of queuing jobs, matching the requirements of a job and the resources available to the cluster, and migrating jobs across the cluster:
Read this article it offers feature, cons and pros of each solution.