Atari ST series Technical Reference Manual page 8

just as GEM does, but with true 68000 speed and with no
intermediary levels of operating systems.
If you're a serious ST programmer, you probably already
own highlighted, dogeared copies of the first two books in
this series. This book will complete your collection and lead
you into hitherto unsuspected levels of programming. If you
are only beginning to explore the world inside your ST, this
book is an excellent starting point.