o·pen-source
adjective
COMPUTING
- denoting software for which the original source code is made freely available and may be redistributed and modified.
Notice is says original source code and freely available. This is the accepted definition of ANY open source software.
For a longer definition:
Generically, open source refers to a program in which the source code is available to the general public for use and/or modification from its original design free of charge, i.e., open. Open source code is typically created as a collaborative effort in which programmers improve upon the code and share the changes within the community. Open source sprouted in the technological community as a response to proprietary software owned by corporations.