It does not appear that there is a similar question to this already posted, so I will go ahead and ask.

I am working on a project that could benefit from having two - four servers handling incoming requests to a backend webservice. The service does not require SSL but does need to support occassional long running processes (upto 120 secs).

This project does not at present have the funding to purchase a hardware load balancing solution.

I have previously used HAProxy as a solution for this, and found it very simple and straightforward. Is there a similar product for windows (server 2003 or 2008) which provides similar configuration options and runs as a lightweight service?

For reasons outside my control I cannot setup a Linux machine (physical or virtual) and so I am looking for behaviour that can be deployed on a windows machine.

I can only find Perlbal which appears to fall into this category. So as not to keep this open indifenitely I will give credit to the only answer.