From: Matthew Flatt <>
Date: Tue, 20 Feb 2001 19:37:27 -0800
Subject: version 199.1

The `exp’-tagged code in the CVS repository is still version 103.x, and
will remain so for several more months.

Meanwhile, MzScheme and MrEd version 199.1 are now available via the
`v200’ tag. (The 199.x series will eventually end with the version 200
release.) This version implements the new module and syntax systems.

*** The `v200’-tagged code is for the adventurous and impatient! ***

Only MzScheme, MrEd, and the collections listed below work. We’ll keep
you posted as the rest of PLT Scheme migrates to version 199.x in the
coming weeks and months.

Library collections that work:

 * compiler (mzc) - mostly, but doesn’t compile module-based code, yet
 * dynext - all
 * errortrace - all
 * launcher - all
 * make - all
 * mred - all, now required to run MrEd
 * mzlib - all, substantially changed
 * net - partial
 * readline - all
 * setup - partial (builds zos)
 * slatex - all
 * syntax - new
 * xml - all

The `v200’ tag has not even been applied to most of the rest of the
plt tree.

Documentation is available in PDF form, though a few details are still

Although many things have changed since 103.x, we plan to change more.
In particular, the class system (now in MzLib instead of MzScheme) is
due for an overhaul.

Several aspects of the C interface have changed, but the changes are
not yet documented. Most notably, "process" has been replaced by
"thread" in many structure and function names (in an effort to make the
C code’s terminology match the Scheme code).

See also the `v200’-tagged plt/notes/mzscheme/MzScheme_200.txt.

With the new lexically-scoped syntax system, MzScheme is much slower to
load and run code from source --- typically five times slower, and
worse for code using units or classes. Loading .zo files is as fast as
ever. You’ll probably want to build .zo files before starting MrEd.

Happy hacking,