Flagfox and its source are free to use and open. You can read the text here as well as the "LICENSE" file in the Flagfox source folder.
The first 2 clauses and the disclaimer are from the BSD license, the second 2 are from the zlib/libpng license, the 5th is a variation of clauses in many other open licenses, and the 6th is custom for Flagfox. Simply put, you can use Flagfox and its source for whatever you need so long as you don't post mods of Flagfox to AMO. You can use portions of the code in your own extension and post it to AMO or make a mod and host it yourself, but not both. Yes, this restriction technically makes Flagfox not 100% "free", however I don't want to end up with the possibility of AMO hosting multiple different Flagfoxes with slight modifications.
Flagfox license
Flagfox license
Last edited by DaveG on Thu Feb 27, 2014 6:08 pm, edited 3 times in total.
Reason: update link to full text
Reason: update link to full text