Maybe it's not "technical issues", but features and support? Allegro CL has a proven GUI toolkit, for example, and now they moved it into the web browser.

FYI: here are the release notes of the recently release Allegro CL 11.0: https://franz.com/support/documentation/current/release-note...

IIRC, Cyc gets delivered on other platforms&languages (C, JVM, ... ?). Would be interesting to know what they use for deployment/delivery.