Deeply immersed in the hacker culture at the MIT AI Lab, characterized by collaborative development and freely sharing software. This environment profoundly influences his later views on software freedom.

Contributes significantly to various software projects at the AI Lab, including the text editor Emacs, which becomes one of his most significant and influential creations. He also worked on ITS (Incompatible Timesharing System).

Begins reimplementing Emacs after a rival editor, TECO, gains popularity. His version, initially called 'Mocklisp', eventually becomes the standard Emacs editor and is freely shared.

Observes a growing trend toward proprietary software and restrictions on sharing, which clashes with the open and collaborative culture he values. This experience fuels his growing conviction that software should be free.

A symbolic event where Stallman is unable to modify a printer driver to fix a bug because he does not have access to the source code. This incident solidifies his resolve to promote software freedom.