After reading a few papers on array languages, I decided to resurrect my array-operations library. Nope, this does not make Common Lisp into APL or Nial, but it does provide a concise DSL for array operations which should integrate well into Common Lisp.
The github page provides a quick tour of the library. The code is (or should be) portable, ANSI-conformant Common Lisp, and comes with unit tests for all functions.
The library previously available under this name (which has been dormant for 3 years) is still available, but it is deprecated.