[p_l]

There's another wordplay in the name.

Namely, that "SB" stands for "Sanely Bootstrappable" - something that the CMU Common Lisp was unable to do

[jojohohanon]

In my first job, grumpy Martin had as one of his many indispensable tasks, to build cmucl. (Itasoftware, one of the main lisp shops of the age)