I have been messing around with LESS lately, I have been researching some compiler options to use with my .NET projects. I came across two options, both seem pretty light weight and easy to use:

• WinLess – My co-worker suggested this option to me. You specify your LESS files and it will go ahead and compile everytime you make changes. I would like to see some more options such as an option to place the css file in a different folder after compilation.
• DotLessCSS – This project complies your file when the app loads for the first time. 

Good luck!