There was a small thread on the Shen Google Group about adding docstrings [1].
There is an BSD version of Shen that can be forked and docstrings added by whomever wants to pickup the work. The language's footprint is small enough now at the moment, that now's the time to get the first chunk done.
The BSD version is pretty impressive, and could be turned into a great project if people picked it up. A lot of interest has been expressed, but it is the commercial version that is moving ahead with lots of improvements. Shen's creator, Mark Tarver has added Griffin, an optimizing compiler, concurrency, and HTML generator in the form of SML (Shen Markup Language).
It is a very fun project. The small set of instructions it is based upon Klambda, has since been ported to many languages - Ruby, Python, Lisp, Haskell and more. The SBCL port is the main one. Aditya Siram (Deech) has just created an Elisp port, shen-elisp! [2]
[1] https://groups.google.com/forum/#!topic/qilang/FHUNMvOyu2U
[2] https://github.com/deech/shen-elisp