Thing I longer wanted to happen is now becoming reality - Gammu is getting new public API. Man reasons for the change are:
ABI stability. - Till now almost every change in internals of any driver lead to ABI change. If we would correctly increase so name on each ABI change, we would be somewhere near 200, what is not something we could be proud of.
Centralisation of variables cleanup. - Currently all phone drivers have to do some common things in each function. New API allows to centralise those operations in one place.
Exposing of internals. - Old API exposed too much of Gammu internals, what could be misused by programmers and could lead to unexpected behaviour when some internals are changed.
The work is not yet still complete, but the API is getting final shapes right now, so you still have chance to change something. While doing such big change, I decided also to complete documentation of all public functions. This is also currently work in progress, but arising API documentation is already available.
If you are developer using Gammu library, you will have to change some things in your code. To document these changes, new Porting guide has been created. I suggest you not to start with this right now as the API is really not complete and might change a lot during next days.