Remmina Plugin Builder is a free software that will ease the process of develop and compile plugins for Remmina.
The stable versions released with source code packages are linked in the Download page.
The Remmina Plugin Builder development version source code is available on GitHub.
Remmina Plugin Builder is distributed as open source code available on GitHub under GNU GPL-2+ license (GNU General Public License version 2 or higher). The software is supplied as is and it doesn't offer any warranty. Anyone can fork the project, modify and distribute it under the same GNU GPL-2+ license.