Any free DWG libraries ?

I'm looking for a free (or free until I begin to distribute my program) DWG libraries.
I'd want to open, modify or create DWG f(Autocad) files.
I Know Intellicad and OPenDWG, but I ask myself if there is some free (or free until I begin to distribute my program)
Thanks

As far as I know there's another library called libredwg under GPL v3.

http://en.wikipedia.org/wiki/LibreDWG

But according to Wikipedia it has it's own licensing problems.