Mentor Graphics is adding some spice to the OS race. They're releasing a software platform based around their proprietary Nucleus RTOS. The platform, initially validated and optimized for Atmel's ARM9-based MCUs, aims to be an out-of-the-box solution for devices with "smart user interfaces," i.e., user interfaces (UI) with advanced graphics, audio, etc. In the press release, Mentor gives a long list of target applications, but the briefing focused primarily on personal media players (PMP).
Mentor is fighting against Windows CE and Linux. The company says that their platform has more complete hardware support (e.g., it has better peripheral support than a standard Linux build) and that Nucleus has a much smaller footprint than WinCE or Linux. Nucleus also offers higher real-time performance by supporting such features as tightly-coupled memory and DMA transfers.
One big disadvantage of Nucleus is that it lacks the large development community of open platforms like Win CE or Linux. Developers working with Nucleus will have access to a much smaller base of existing code. To ameliorate this disadvantage, Mentor offers Inflexion, an "advanced UI engine" that allows designers to use drag-and-drop tools to quickly generate code. According to Mentor, it is much easier to build a UI with inflexion than it is to build a UI using Linux or WinCE. For resource constrained applications, this platform looks like a compelling option.