From: "Paul Steckler" <>
To: <>
Date: Thu, 30 May 2002 13:37:33 -0400
Subject: [plt-scheme] PLT Scheme v200alpha19 available

PLT Scheme v200alpha19 is now available.


A new alpha release of DrScheme v200, alpha19, is available now from

There have been many bug fixes and small improvements since the alpha1,

alpha9, and alpha12 releases.  Those who have installed earlier alphas
are encouraged to download this new release.

For those who did not see the announcement of the earlier alpha
releases, the following information may be helpful in deciding whether
to download alpha19.

DrScheme v200alpha19 is incompatible with v103 in many ways:
The teaching languages are slightly different;
the stepper is not ready; and DrScheme has not been tested
as thoroughly.  Teachers and students using DrScheme in
coursework should wait for the final 200 release, expected soon.
Others should upgrade with caution.

For those who can upgrade, however, v200alpha19 is likely to
work significantly better than 103.  On the surface, DrScheme
looks much as it did in version 103, but it tends to load
programs faster, provide better error messages, and adapt
more easily to new variants of Scheme.  Below the surface,
v200 is organized around a new module system that simplifies
many tasks, such as managing multi-file programs, developing
syntactic extensions, compiling with mzc, and building
stand-alone executables.

The improvements include:

 - DrScheme now provides a fully-compliant R5RS language,
    including hygienic macros.

 - New languages can be added to DrScheme easily.  See
    the Tools manual for details.

 - The PLT Scheme language includes a new namespace-managing
    `module’ form (which complements the component-defining
    `unit’ form).

 - TeachPacks now support macro definitions (v103 TeachPacks
    are not compatible with v200 DrScheme, however).

 - A Web server provides support for developing fast, interactive

 - XML can be interspersed with Scheme code in the DrScheme
    definitions window

 - DrScheme’s GUI interface supports French, Spanish, German,
    and Danish, as well as English

 - The space used for the Definitions and Interactions
    windows in DrScheme is interactively resizable.

 - Dorai Sitaram’s Teach Youself Scheme in Fixnum Days is
    included in the DrScheme documentation, and his tex2page
    TeX-to-HTML processor is included as a collection.

 - An online version checker makes sure the installed versions
    of DrScheme and other packages are up-to-date.

DrScheme v200alpha19 is available for

 - Sparc Solaris 8
 - Linux (tar.gz and RPM formats)
 - Windows (95/98/Me/NT/2000/XP)

Please note that DrScheme and MzScheme v200alpha19 are available for
Mac OS X, but not for the Mac Classic platform.  The support for
Mac OS X is in work-in-progress; the latest code is available from the
PLT CVS server.  See http://www.plt-scheme/org/anoncvs/ for access


-- Paul

| Paul Steckler                                |
|                            |
| "I’m the type-checker; I’m here to help you" |