Novamente, the successor to WebMind, implements LISP-like internal constructs as a core part of its design. From the Novamente FAQ under the “Why C++?” section:

Novamente’s “internal procedures” are autogenerated (by internal learning procedures) by the system in a language called Combo that has more in common with LISP or Haskell than C++ (it’s purely functional).

Combo is a simple programming language designed (mainly by Moshe Looks) for use within the Novamente Cognition Engine. Novamente Schema are represented internally in a format that is easily translatable into textual Combo programs. Combo has been described as “LISP with a bad haircut,” and with a bunch of primitives designed specifically for interaction with other aspects of the Novamente system.