Our 16X PWM LED FADER board is now completely open source. The firmware (mplab project in C), schematic and layout in kicad, and BOM are all available. Hopefully this project will be a good starting off point for someone needing high resolution PWM control of mosfets, and lots of them.
The brain is a dsPIC33FJ32GS608, which features 16+ PWM outputs with 1.04ns duty cycle resolution. This is used to provide full 16bit control over 16 channels, with a very fast update rate. With SPI, you can send commands fast enough to smoothly fade all 16 channels, although many fades and chases are built in. A simple command / value protocol accepts control from SPI, 5V UART, or RS232.