I found it.
Dragonfly is free! This means free of charge for personal use. Dragonfly may be copied and distributed, provided that this copyright notice is kept intact. There cannot be a charge for the use of Dragonfly to anyone else. The copyright holders (Mark Claypool and WPI) reserve the right to reclassify this software as non-freeware at a later date (e.g., as shareware). Doing so will not modify the license agreement of any previously distributed executables.