If you want to contribute something to the ApCoCoALib, you must know how to write C++ code, and you must write your code in such a way that it fits into the ApCoCoALib. There are some coding guidelines which you should follow. In case you want to contribute high-level CoCoAL code to ApCoCoA, please follow the steps described in ApCoCoA:Contribute.
The mathematical framework
ApCoCoALib is a library implementing mathematical methods based on the field of computer algebra and Groebner basis computations - both symbolic and numeric. If your code is related to these topics, you're welcome to contribute!
So you decided to contribute to the ApCoCoALib. Great! Please leave a message in the ApCoCoA Development or ApCoCoA User board, describing what your code does. Eventually you may already want to publish the code itself. The best way to do this is to create a diff file by comparing the original ApCoCoALib source tree and your changed source tree. If you have problems creating this file please let us know in your message and we will help you out.
As an example for this procedure please consider this thread in the forum.
As soon as you made your code available to us, one of our 'core ApCoCoA developers' (most likely Michael Abshoff) will check if it compiles and does not leak memory. We will keep you informed about the status of your contribution.