Bywater BASIC interpreter.
A BASIC interpreter
by Ted A. Campbell which implements a large superset of the ANSI Standard for Minimal BASIC (X3.60-1978) in ANSI C, and offers a simple interactive environment including some shell program facilities as an extension of BASIC. The interpreter source has been compiled successfully on a range of ANSI C compilers on varying platforms including MS-DOS, Unix, and Acorn RISC OS.
Version 2.10 was posted to news:comp.sources.misc, volume 40.