The BeRTOS project, an open source real-time kernel and support library for embedded systems, comes with a commercial SDK. The SDK simplifies the development and provides a development environment with tools for debugging and flashing, as well as including priority support.
We will look more at BeRTOS in the future. In the mean time, the SDK edition includes two USB product IDs. This means that you do not have to get such IDs from the USB Implementer’s Forum – something that can cost more than the entire SDK. So, if you need IDs for your next project, and want an open source real-time OS with support and tools, you know where to go.