First developed as Multi-Tool Word by Charles Simonyi, developer of the first GUI word processor (Bravo), in 1981, Microsoft’s word processor would soon be renamed Microsoft Word after its release for both Xenix and MS-DOS. For a time, the Mac port, Word for Mac, was the height of popularity. But the word processor really came into its own with Word for Windows (codenamed Opus for the existential penguin from Berkeley Breathed’s comic strip Bloom County), released in 1989. It became the market leader for IBM PC-compatible computers following the release of Windows 3.0 in 1990.