Speaking out against the practice of proprietary and closed software was an MIT Lab programmer called Richard Matthew Stallman, or RMS as he prefers to be called.
Working at MIT labs, several episodes warned him about how proprietary and closed software was imposing severe limits to their users’ freedoms. He believed that users should be free: free to create, to study, to use, to reproduce, to share, to modify, and to do with software what they wanted. The principles of free software were born.
Sometimes people get confused about what “free” means in this context. RMS has often explained that what he means by “free” is “free as in free speech,” not “free as in free beer.” That is, free software should not necessarily be given away for free, but it definitely should not limit in any way what the user can do with it.
He set himself the task of creating an OS and enough applications to make proprietary software unnecessary, in a collaborative project he called GNU. This is a recursive acronym (and programmer’s in-joke) that means “GNU’s Not Unix!” Although the goal was to make it UNIX-like, it was meant to be entirely free and rigorously excludes any UNIX code. The project was first announced on September, 1984, and started development a few months later.
They had to write the core of the OS, or kernel (which was given the name HURD), and a set of applications that reproduced the operation of UNIX. The latter part advanced swiftly, but development of the kernel stalled. It soon reached a point in which the only part missing from the free UNIX-like utopia was the kernel.
As part of his efforts, Stallman also created the Free Software Foundation, which, as its name implies, advocates for the use of free software.