Open Source Load Balancers

Quartz.NET is a full-featured, open-source job scheduling system that can be used from smallest apps to large-scale enterprise systems. Can run embedded within an application or even instantiated as a cluster of stand-alone programs (with load-balance and fail-over capabilities). Jobs are scheduled to run when a given trigger occurs, triggers support wide variety of scheduling options. Jobs can be any .NET class that implements the simple IJob interface, leaving infinite possibilities for the work jobs can perform. Job stores can be implemented to provide various mechanisms for the storage of jobs, in-memory and multiple relational databases come supported out of the box. Built-in support for load balancing your work and graceful fail-over. Applications can catch scheduling events to monitor or control job/trigger behavior by implementing one or more listener interfaces.

OpenJCS (Job Control System) is a batch scheduling and control system for use on Unix systems which uses load balancing, dependency control, scheduling, runbooks, queueing and resource allocation subsystems for unmatched scalability and flexibility.