[plt-scheme] PLT Scheme v200alpha19 available

["Paul Steckler" <steck@ccs.neu.edu>]

PLT Scheme v200alpha19 is now available.

THIS IS AN ALPHA RELEASE.

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

  http://download.plt-scheme.org/

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 
    servlets

 - 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
details.
	
Enjoy!

-- Paul

 ----------------------------------------------
| Paul Steckler                                |
| steck@ccs.neu.edu                            |
| "I'm the type-checker; I'm here to help you" |
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