The package enables ‘command sequence recognition’ on all text in maths mode. In this state, an consecutive sequence of two or more letters, delimited by non-letters, will be checked to see if it is the name of a current control sequence. If the command is so recognised, the letters will be replaced with the corresponding control sequence.

The package reportedly works both with Plain TeX and LaTeX, but has an interesting list of ‘issues’…

The author is Robert H Wentworth. The package is Copyright © 1990 Robert H. Wentworth.