It seems that the C language is sweeping all before it at the popular end of the artificial intelligence market, and for release 3, Expertech Ltd, Slough, Berkshire has rewritten its Xi PLus expert system shell in C, and is thrilled with the resulting speed and improved performance over release 2: the new release supports knowledge bases two to four times larger than its predecessor, there is a more powerful dictionary, more scope for knowledge base comment, pop-up menu, built-in MS-DOS command facility and VGA support; no price given.