Developed by Kent Dybvig, sold to Chez which did who-knows-what with it (hiring Dybvig as well) but never commercialized it directly, and then open-sourced by Cisco.
"Cadence Research Systems" (CRS) was Kent's company. The system was "Chez", and was a commercial product of CRS since the '80s. Kent sold CRS (and thus Chez) to Cisco in 2011, and they didn't commercialize it directly, but happily it was open-sourced in 2016.