WEBLicense. GNU GPL, GNU LGPL, GNU AGPL, GNU FDL, GNU FSDG [1] [2] Official website. gnu.org. GNU ( / ɡnuː / ⓘ) [3] [4] is an extensive collection of free software (385 packages as of September 2023 [5] ), which can be used as an operating system or can be used in parts with other operating systems.