Today we released yet another open source project: #usblib (SharpUSBLib). The history for this project is quite similar to many other OS projects ("scratching an itch"): Mike built a terrarium for his soon-to-be-delivered chameleon, and he wanted to manage the ligthing using a USB-controlled power switch. Not having found a suitable USB library for .NET, he decided to write one himself.
The library is used for low level access to USB devices, and it works under WIN32/.NET and Linux/Mono. Documentation can be found in the wiki, a support forum also exists. The download includes source code for this dual-licensed (GPL and LGPL) library.