The Shen kernel went open source in February 2015 when it transitioned to a 3-clause BSD license under version 19.
4. The Core Language
4.6 Sequences
5 Defining Functions
6. Packages
7. Shen-YACC
8. Shen Prolog
9. Types
10 Sequent Calculus
10.2 Exotic Types
Built by Shen Technology (c) Mark Tarver, September 2021