[PLT announcement] PLT Scheme v200 available

[Paul Steckler]

PLT Scheme v200 is now available from=20

  http://download.plt-scheme.org/=20

We urge all users to upgrade to this new, stable release.=20

The new release dramatically improves previous releases in many ways.=20
The improvements include:=20

 - 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.=20

   For details, see=20

     Matthew Flatt. Composable and Compilable Macros: You want it when?=20
     ICFP 2002. To appear. See http://www.cs.utah.edu/plt/publications/

   The implementation of PLT Scheme is based on the new module system.=20

   The framework also provides constructs for attaching assertions to
the=20
   exported values of a module. See "contracts" in Help Desk. For
details=20
   on the underlying concepts, see=20

     Findler, Felleisen. Contracts for Higher-Order Functions.=20
     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.=20

 - New languages can be added to DrScheme easily. See the Tools manual
for
   details. An example, Algol 60, is available from our contributions
Web=20
   site: http://www.cs.utah.edu/plt/develop/.=20

 - 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).=20

 - 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.=20

 - 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:=20
     Dorai Sitaram. "Teach Youself Scheme in Fixnum Days". 2000-2002.=20
     http://www.ccs.neu.edu/home/dorai/t-y-scheme/t-y-scheme.html
   =20
 - 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.=20

 - An online version checker makes sure the installed versions=20
   of DrScheme and other packages are up-to-date.=20

DrScheme v200 is available for=20
=20
  + Windows (95/98/Me/NT/2000/XP)=20
  + Mac OS X=20
  + Linux (tar.gz and RPM formats)=20
  + Sparc Solaris 8=20

  * Other Unix (source code)
    Source code is easily compilable on most other Unix platforms.=20

  - 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=20
feedback, especially the users who braved our alpha releases in=20
good cheer.=20

Enjoy!

-- Paul