CoCoA and ApCoCoA are open source projects. They are open for you to contribute. This means, you can extend this software, by adding your packages or c++ code to CoCoA or ApCoCoA. The procedures how to achieve this are described in four different articles, namely CoCoA:Contribute, CoCoALib:Contribute, ApCoCoA:Contribute and ApCoCoALib:Contribute. In general, it will be easier to submit your developments to ApCoCoA. It can become then -in a later stage- part of CoCoA if you and the CoCoA-Team wish so.
In case you want to contribute but do not know how or what to contribute, please leave a message somewhere in the forum.