Unfortunately, the "X-factor" is a relatively well-known and verified marketing gimmick. The "eFactor" is probably passe as a relic of the dotBomb era. The "iFactor" has some merit, but runs afoul of both Apple and variable naming conventions for integer types.

How about: "The language formerly known as {unpronouncable symbol}" ... carries a certain mystique, and stylishly reduces to simply "The Language."