MacinTalk is the name for the Macintosh text-to-speech system. It has existed since before the very first Macintosh came out in 1984.
Its first public demonstration was the annual Apple shareholders' meeting in 1983. Steve Jobs unveiled the Macintosh, then told the audience that it was going to explain itself. It recited a speech, introducing itself and making fun of IBM.
MacinTalk's development was mostly inactive from then on. Quality Computers, eventually a division of Scantron, released a package of utilities that used the original MacinTalk libraries, but it wasn't until the first Power Macintoshes were released that MacinTalk became fully mature.
In 1994, for the Macintosh's tenth anniversary, Apple totally revamped MacinTalk. There were, in fact, TWO new versions. MacinTalk 2 had some new voices, some with robot sound effects or songs, which were easier to understand than original (which sounded like a Speak & Spell), but they weren't mistakable for a human. MacinTalkPro, however, was a knockout. The four voices, named simply MacinTalk Pro (Male|Female) (High|Low)-quality, ate gobs and gobs of memory and CPU resources; non-PowerPC Macs could handle the MacinTalk 2 voices with enough RAM, but the Pro voices would only stutter on all but a Power Macintosh.
In addition, these new versions could speak Spanish!
Unfortunately, not many people have been able to successfully integrate text-to-speech with current user interfaces. Other than speaking the contents of the screen for the visually impaired, its usefulness is limited. MacinTalk has thus been relegated to use in techno music and foley pits.