[plt-scheme] PLT Scheme v200 available

PLT Scheme v200 is now available from 

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

We urge all users to upgrade to this new, stable release. 

The new release dramatically improves previous releases in many ways. 
The improvements include: 

 - The PLT Scheme language includes a module system that properly
   integrates macros and modules. The macro module system enables
   programmers to write different modules of a product in different
   languages, yet preserves the ability to compile modules separately. 

   For details, see 

     Matthew Flatt. Composable and Compilable Macros: You want it when? 
     ICFP 2002. To appear. See http://www.cs.utah.edu/plt/publications/

   The implementation of PLT Scheme is based on the new module system. 

   The framework also provides constructs for attaching assertions to
the 
   exported values of a module. See "contracts" in Help Desk. For
details 
   on the underlying concepts, see 

     Findler, Felleisen. Contracts for Higher-Order Functions. 
     ICFP 2002. To appear. See http://www.ccs.neu.edu/scheme/pubs/

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

 - DrScheme includes a graphical module browser. 

 - New languages can be added to DrScheme easily. See the Tools manual
for
   details. An example, Algol 60, is available from our contributions
Web 
   site: http://www.cs.utah.edu/plt/develop/. 

 - The teachpack implementation interface has changed because teachpacks
can
   now add new syntax to a language level. The user interface of the
   existing "How to Design Programs" (HtDP) teachpacks remains the same.


 - A new collection, parser-tools, supports the generation of lexers and
   parsers for LALR(1) grammars. Unlike conventional lex and yacc
   implementations, the PLT variants support the specification of
grammars
   and related code in a single file. The embedding of Algol 60
   demonstrates this point and also shows how source information is
   propagated through the elaboration and interpretation process.

 - Programmers can now mix XML syntax and Scheme syntax in the
Definitions
   window via embedded editors (see the "Special" menu). 

 - PLT Scheme now includes a Web server that offers special support for
   interactive servlets. DrScheme supports the development of such
servlets
   in the conventional incremental manner; use the servlet.ss teachpack
for
   the HtDP teachpack. A "Create servlet" mechanism, analogous to the
   "Create executable" mechanism, is forthcoming.

 - DrScheme supports a tool for profiling code. 

 - DrScheme's Definitions and Interactions windows are re-sizable.

 - In addition to English, DrScheme's GUI interface supports Danish,
   French, and Spanish. A partial version of German is also available.
   Improvements and additional languages are welcome contributions.

 - The documentation includes the on-line book: 
     Dorai Sitaram. "Teach Youself Scheme in Fixnum Days". 2000-2002. 
     http://www.ccs.neu.edu/home/dorai/t-y-scheme/t-y-scheme.html
    
 - v200 includes the tex2page TeX-to-HTML converter. It was used
   to produce the on-line versions of SICP and HtDP and our own
   documentation. 

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

DrScheme v200 is available for 
 
  + Windows (95/98/Me/NT/2000/XP) 
  + Mac OS X 
  + Linux (tar.gz and RPM formats) 
  + Sparc Solaris 8 

  * Other Unix (source code)
    Source code is easily compilable on most other Unix platforms. 

  - PLT Scheme v200 is not yet available for the Mac OS Classic
platform.

  - A follow-on release, v201, with additional improvements, is expected

    late this summer.

The PLT Scheme crew thanks its many users for their invaluable 
feedback, especially the users who braved our alpha releases in 
good cheer. 

Enjoy!

-- Paul