MIT Technology Review revisits the 50-year history of Emacs, which began at MIT in 1976. Incompatible TECO editing macros complicated collaboration, prompting developers to assemble common capabilities and establish a culture of modifying the editor and sharing improvements. Its significance extends beyond longevity: extensibility and shared conventions turned a personal tool into collaborative infrastructure. GNU’s official history dates GNU Emacs to 1984, so its origins should not be conflated with those of the original Emacs.