[3] Later, wishing to move on and after a failed search for people who would maintain it under the same rights, he finally sold his version of Emacs to UniPress because they agreed to sell it under reasonable terms.
The dispute between Richard Stallman and UniPress inspired the creation of the first formal license for Emacs, which later became the GPL, as Congress had introduced copyright for software in 1980.
[4] Gosling Emacs was especially noteworthy because of the effective redisplay code,[5] which used a dynamic programming technique to solve the classical string-to-string correction problem.
The algorithm was quite sophisticated; that section of the source was headed by a skull-and-crossbones in ASCII art,[6] warning any would-be improver that even if they thought they understood how the display code worked, they probably did not.
[11] UniPress never took legal action against Stallman or his nascent Free Software Foundation,[citation needed] believing "hobbyists and academics could never produce an Emacs that could compete" with their product.