Trail of crumbs from searching the web

A significant paper

Scheme Mechanics Installation for GNU/Linux or Mac OS X (MIT),
Installing MIT Scheme (U Minnesota),
Using MIT-Scheme in MacOS X on the Command Line (Ingram),
MIT/GNU Scheme 9.2 (gnu),

Just now on my machine MScheme gets MIT Scheme from gnu on command line.
while mechanics gets MIT Scheme from MIT in X11.
Scheme gets MzScheme version 352.

In X11:
Cht gets you tutorial
Cxb gets you Scheme
Type 1 <return> to “get a buffer”
type expression
CxCe evaluates what you typed
Value shows up at bottom.

Beware the semantics on page 203. They might contract when they should not.