Edward R. Ford created the Shapeoko on Kickstarter at about the same time Bart Dring was doing his Makerslide Kickstarter — the synergy was obvious, and the Shapeoko was redesigned to use Makerslide.
Zach Kaplan contracted with Edward to distribute the Shapeoko (which was originally designed to have an 8" x 8" x 3" working area, cost $300 and fit in a USPS flat rate box to save on shipping), then Edward and Bart were hired and the Shapeoko 2 was developed.
Edward left Inventables to join a competitor which had just launched a machine on Kickstarter, and developed the Shapeoko 3 as a clean sheet design, applying everything learned from the previous machine designs — the only parts in common are the M5 bolts, eccentric nuts, precision spacers, and Delrin V wheels. Bart Dring when hired had stated that he would only stay for a fixed time, and then retire, which he did.
The X-Carve was developed as a cosmetic fork which gradually added new extrusion profiles to reduce parts count and simplify assembly, and the Carvey was added to the lineup (which is a competitor to the afore-mentioned competitor’s Kickstarter machine).
There’s a history page on the Shapeoko wiki which has most of the above dates.