The GNU Project
It’s older than you think, unless you know that it was begun in 1983, in which case it’s exactly as old as you think. But it goes back even farther, of course; Richard Stallman was concerned with the issues of software freedom and copyright abuse three years earlier, when he railed against “time bombs” in the Scribe word processor and struggled with Xerox over access to a shared laser printer’s source code.
Stallman was one of them (perhaps, as some say, the Last). He took the previously-unspoken (well, more or less) Hacker Ethos and fashioned the GNU Manifesto and the philosophy of “free software”. Stallman is careful to distinguish between free (as in, no cost) and free (meaning you can do whatever you like with it). He uses the analogies of “free speech” versus “free beer”, which couldn’t be plainer, but at the time things were a little more confused.
Things got even more muddled after 1998, when the Open Source movement splintered off to champion the ‘transparency’ of code rather than the virtues of freedom (which may be more difficult to sell). The basic rule of thumb is that free software promotes sharing and collaboration; it is an ideal rather than a practicality, but an ideal whose long-term practicality is even greater.