The GNU Manifesto Alive
Stallman's call to arms — software as commons, 'free as in freedom.' The document that created the free software movement and, eventually, the license the world's infrastructure runs under.
Written in 1985 after Stallman left the MIT AI Lab, the manifesto argued software should be free — 'free as in free speech, not free beer' — and announced the GNU project to build a Unix-compatible free system. It asked for programmers, donations, and manufacturers to adopt it.
The GPL license it led to enforced sharing through copyright — 'copyleft' — and the kernel GNU never quite finished was supplied by Linux in 1991. The manifesto remains the ideological founding document of free software and the origin of most open-source licensing debates.