Prior to May 2002, eCos was released under
the Red
Hat eCos Public License (RHEPL). The RHEPL required any
modifications to eCos code to be made
available under preferential terms to Red Hat and was therefore
incompatible with code licensed under the GPL. The use of
eCos source code which was licensed under
the RHEPL is not affected by the switch to the modified GPL for later
revisions.