X. J. Scott
Jeff Scott invented pitch bend microtuning in the late '80's. Others have followed, who copied parts of his design for their own (commercial) microtuning projects, down to the level of using terms like 'scale layer' to refer to having multiple tunings available for a single instrument on different channels.
He developed Nuscale, the first software program to incorporate pitch bend microtuning, which was originally for the Atari ST. The first public demo of Nuscale was 1989. The first public internet release of Nuscale was 1994. He later incorporated it into L’il Miss' Scale Oven™ (LMSO) for Mac, which also had a built in microtonal synthesizer.
Besides pitch bend microtuning, he was first to invent what has now become prior art like bundling a synthesizer with a microtuner, preset scales, using MIDI, having tuning tables, and handling MIDI controllers like sustain, although he has chosen not to patent these novel and useful inventions. To the contrary, he has been happy that his inventions have been adopted in many other microtuning devices because microtonality has been his passion for decades and it is important to him that the art and practice of microtonality gets promoted, together with the ability to work microtonally with as many instruments as possible.
1. Personal email exchange between Jeff Scott and Bo Constantinsen (13 April 2016).
2. Forum post by Jeff Scott on his nonoctave website's forum (now offline), re-posted by Carlo Serafini (on 28 August 2008 at the electro-music Forum) and permanently archived at the Wayback Machine and WebCite.