Typically other packages will end up as other libraries that need to be linked with the application code. These other packages may be covered by different licenses, and application developers should make sure that the requirements for all licenses are satisfied.

Some companies or organizations may release packages that are not open source or freely available. Instead the application developer may have to pay a one-off license fee or quite possibly per-unit royalties if the application uses such a package. Not only is this perfectly legal, Red Hat would very much like other companies to make money by providing such packages.

Some packages may be released under the eCos public license without becoming part of the core system. Typically this will happen if the eCos maintainers believe that they would be unable to maintain such a package themselves, for example because it relies on special hardware.