The Programmer Who Killed Modes

In 1973, Larry Tesler joined Xerox PARC, the research lab that was inventing the bitmapped graphical interface. The dominant text editor of the era was a moded program: you pressed a key to enter "insert mode," typed, pressed another key to leave it, and hoped you remembered which mode you were in. Misremembering corrupted the document. Tesler hated this.

With Tim Mott, he wrote Gypsy in 1974–75 — a word processor for the Xerox Alto with no modes at all. You selected text by dragging the mouse, and any keystroke acted on the selection. Gypsy introduced the verbs cut, copy, and paste, named after the literal scissors-and-glue workflow editors used on paper. The same trio is in every text field on every operating system today.

Tesler left PARC for Apple in 1980, recruited after Steve Jobs's Apple delegation toured PARC and saw the Alto. He worked on the Lisa, the Macintosh, and later the Newton. His California license plate read NO MODES. His personal email signature for years included "Don't mode me in."

The paradox is that modes never actually went away. Vim still has them, and so do most professional tools. What Tesler killed was the assumption that a personal computer should default to one. He died in February 2020, and obituaries in the Times and the Guardian quoted the plate.