UCAPA (Unofficial C++ API for Parrot ARDrone 2.0) is a cross-platform API for the Parrot ARDrone 2.0. For developers, UCAPA is available under MIT licence (see LICENSE file for detailled terms).
You can find informations about how to use the API in the COMPILE file.
The documentation can be generated with doxygen. Example applications using the API are also available.
UCAPA is an open-source project. So don't hesitate to post suggestion, bug reports and pull requests.