Balancing the needs and desires of all the companies, organizations, and individuals involved with eCos is difficult. The most important requirement is that the freedom of all eCos users is protected: it must be impossible for anybody, even Red Hat, to impose restrictions on how the system can be used now or in the future. Some existing licenses such as the X11 license do not provide this.

It is also desirable that all enhancements are made available to the community as a whole, thus improving the system and making it even more attractive to potential users. Some existing licenses such as the BSD license do not provide this.

The GNU Public License does meet these requirements, but it goes further: all applications that get linked with GPL'd code are also covered by the GPL, which means in practice that application developers have to make the sources available. In the embedded systems market this requirement is generally considered unacceptable and many companies refuse to use any GPL'd code as a result. This would reduce the uptake of eCos, and we want as many people as possible to use the system.

The Netscape Public License came closest to meeting the requirements. There were some modifications to reflect the needs of embedded system developers, and the result was the eCos public license.