From: steck@rice.edu (Paul Steckler)
Newsgroups: comp.lang.scheme
Date: 1998/03/28
Subject: DrScheme v51 released

DrScheme v51 is now available from the Rice University
Department of Computer Science Web site,
http://www.cs.rice.edu/CS/PLT/packages/drscheme.

DrScheme is a graphical development environment for Scheme. It runs
under Windows 95/NT, MacOS, and X Windows. The underlying Scheme
implementation is MzScheme.

DrScheme’s features include:

  o source text highlighting of syntax errors
  o source text highlighting of run-time errors
  o support for multiple levels of Scheme from
      “beginner” to “advanced”
  o interactive and graphical static analysis

The underlying language supports

  o an object system
  o a toolbox of simple drawing commands suitable for
      simple drawing
  o an advanced graphical user interface (GUI) library

Here are the release notes for v51.

The Future
----------

PLT intends to conduct a major release by the end of this year or early
next year. The changes will directly affect users of MrEd, the graphical
toolbox. Please expect deletions of features, additions, and a few
modifications. DrScheme will migrate to a graphical multi-module
environment.  This change should not affect beginners or teachers.

New Programs
------------

DrScheme Jr is a new text-only version of DrScheme.  It requires fewer
resources, but provides only a read-eval-print loop with
line-column-based error messages.  DrScheme Jr does not provide a
built-in program editor or a graphical toolbox.

mzc is a new compiler that transforms MzScheme programs to native code
libraries. mzc is not yet an optimizing compiler; the
performance of its output is comparable to running the Scheme source
directly in MzScheme.

MrSpidey
--------

MrSpidey is now distributed as a separate tool.  Download instructions
are provided when downloading DrScheme.  When installed, MrSpidey may
be invoked from DrScheme.

Networking facilities
---------------------

The networking-related routines have now been incorporated into the
distribution.  They are in the collection `net’, and consist of the
packages

o cgi provides routines for writing CGI scripts

o nntp communicates with a Usenet server

o pop3 communicates with a POP-3 server

o url parses and establishes HTTP connections

o mail sends email (preliminary, currently only works under Unix)

Documentation is in a subdirectory `docs’, of the net collection
directory.  That subdirectory contains files named package.txt, where
package ranges over the above names.

Miscellany
----------

There is a new DrScheme vocabulary named "MrEd".  This vocabulary does
not provide source correlation for errors, but allows fast parsing and
execution.  In the next release, the MrEd vocabulary will become a
language level.

Console I/O has been sped up, and is interruptible by using the Break
button.

See the HISTORY files in notes/drscheme, notes/mzscheme, and
notes/mred for descriptions of other bug fixes and minor changes.

-- Paul

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| Paul Steckler              |     Rice University PLT           |
| steck@cs.rice.edu          |     DrScheme Project              |
| Tel:  713/527-8101x3814    |     http://www.cs.rice.edu/~steck |
| FAX:  713/285-5930         |     *** Ad astra per hackera ***  |
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