pdaxrom is mostly open source ( there maybe some exceptions like the sd driver which is binary only, from sharp ).
A software you write for pdaxrom can be proprietary, you must check the license of the libraries you use though.
For instance if you application uses only the X libs and the glibc, then you can choose not to release your sources, if you use Qt you will need either to buy a license from trolltech or to release your sources.
