LibrePilot started as a fork of OpenPilot in 2015. The original core team developed much of OpenPilot, but circumstances led to the start up of LibrePilot.
The formal organization is yet to be set up.
If you would like to contribute, pop over to http://forum.librepilot.org and introduce yourself.
There are many tasks to be done in addition to coding the software, like testing, documentation or GCS translations so your support would be most welcome!
Developers should start with Git Workflow page in Developer Manual.
All the software is released under the terms of the GNU General Public License by the Free Software Foundation, version 3 or later. License details are included in the source code headers. You can also write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA for a copy. It is also available here: https://www.gnu.org/licenses/gpl.html
The wiki and other documentation is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported Licence (CC BY-SA 3.0): http://creativecommons.org/licenses/by-sa/3.0/