Trivial shell is a simple platform independent interface to the underlying Operating System. It forks and builds on the code in Kevin Rosenberg's handy KMRCL tools. More details can be found on its home page at Presently, the package is quite rudimentary (even for something trivial !) but we all live in hope.

Personal opinion: trivial-shell had its time, but uiop:run-program and its front-end inferior-shell are more portable, more robust, more featureful, more widely used, and uiop:run-program is already part of your implementation-provided asdf 3. Use uiop and/or inferior-shell instead. — Fare Rideau
ASDF-install package (obsolete)