SJT> We want an engine that will be usable on all platforms we SJT> support, an efficiency improvement on most of them, and a big SJT> efficiency improvement on as many as possible. How many of the Scheme implementations mentioned does are ruled out by this commitment (to which I totally agree) ? Holger -- --- http://www.coling.uni-freiburg.de/~schauer --- "Aus dem gleichen Grund gefällt mir auch Babylon5 besser als Star Trek." -- Aus "Wie starte ich einen Endlosthread ?", Teil 666