NARS2000

The first NARS (Nested Arrays Research System) was designed and implemented in the early 1980s as a testbed for new ideas in APL, principally with nested arrays.

NARS2000 is an open-source APL interpreter written by Bob Smith, a prominent APL developer and implementer from STSC in the 1970s and 1980s. NARS2000 contains advanced features and new Simple scalars and runs natively on Microsoft Windows, and other platforms under Wine.

Language ideas include new functions, operators, and datatypes. The project is free open source Software.