Microsoft has released the source code of its Windows CE 3.0 embedded operating system to developers in hopes of competing with popular open source software models. Although Microsoft is releasing the code through its own 'shared source license' rather than a traditional open-source license it is still a momentous occasion any time Microsoft releases the source to any of its highly protected software.

Under Microsoft's 'shared source license' developers are shown the code, and they may make modifications as they see fit, however, it is not permitted for any developer to distribute the code for commercial purposes. This is vastly different from the open-source systems allowing free distribution rights of modified code.

The highly protected nature of Microsoft’s source code has caused a few developers to be wary of downloading the Windows CE source code. The fear is that if they have downloaded the source code Microsoft could claim that they've copied Windows code in their own software. In such a case it is believed that Microsoft would use the fact that the source code had been downloaded as evidence.