thumb|right|MQuintus performing the Free Software Song along with the audience at German hackerconference 30C3
The Free Software Song is a filk song by Richard M. Stallman about free software. The song is set to the melody of the Bulgarian "Sadi Moma".
A version of this song is also performed by a band (the GNU/Stallmans) during the credits of the documentary Revolution OS. In 1998, Matt Loper recorded a techno version of the song. Jono Bacon also recorded a heavy metal version of the song, and the band Fenster recorded a rhythmic version. In addition, there is a Spanish pop punk version recorded by ALEC, and a Rick Astley mashup, "Never Gonna Give GNU Up".
A version is used in the free software karaoke video game Sinatra.
Lyrics
:Join us now and share the software;
:You'll be free, hackers, you'll be free.
:Join us now and share the software;
:You'll be free, hackers, you'll be free.
:Hoarders can get piles of money,
:That is true, hackers, that is true.
:But they cannot help their neighbors;
:That's not good, hackers, that's not good.
:When we have enough free software
:At our call, hackers, at our call,
:We'll throw out those dirty licenses
:Ever more, hackers, ever more.
:Join us now and share the software;
:You'll be free, hackers, you'll be free.
:Join us now and share the software;
:You'll be free, hackers, you'll be free.
The lyrics have been placed in the public domain.