[racket-dev] Release Announcement for v5.1

If there's no other changes, this will be the final version.

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Racket version 5.1 is now available from

  http://racket-lang.org/

The most significant change in version 5.1 is a rewrite of the GUI
library:

  http://blog.racket-lang.org/2010/12/racket-version-5.html

Unix/X users will see the biggest difference with this change,
because DrRacket and all Racket GUI programs now take on the desktop
theme for menus, buttons, and other GUI widgets.

In the long run, Racket GUI programs on all platforms will improve
as a result of the library rewrite.  In the short run, beware that
this first release of a new library will inevitably include a new
set of bugs.

Version 5.1 changes in more detail:

* The `racket/draw' library -- which implements the drawing half the
  GUI toolkit -- can be used independent of the `racket/gui/base'
  library and without a graphics display (e.g., without an X11
  connection).  Similarly, the racket/snip library -- which
  implements things like images in student programs -- can be used
  independently from racket/gui/base.

  The new library has one small incompatibility with the old GUI
  toolbox: 'xor drawing is no longer supported.  The new library has
  many additional features: rotation and general affine
  transformations, PDF and SVG drawing contexts, gradients, and
  alpha-channel bitmaps.

* The GRacket executable is no longer strictly necessary for running
  GUI programs, because the `racket/gui/base' library can be used
  from Racket.  To the degree that a platform distinguishes GUI and
  console applications, however, the GRacket executable still offers
  some additional GUI-specific functionality (e.g., single-instance
  support).

  The new `racket/gui/base' library includes small incompatibilities
  with the old GUI toolbox: the `send-event',
  `current-ps-afm-file-paths', and `current-ps-cmap-file-paths'
  functions have been removed.  The `racket/gui/base' library
  re-exports `racket/draw', so it includes the same drawing
  functionality as before (except for 'xor drawing).

* The Web Server includes a backwards incompatible change that
  prevents X-expressions and lists of bytes from being directly
  returned from servlets.  This change will increase performance for
  those types of responses and allow easier experimentation with
  response types.  Please see "collects/web-server/compat/0/README"
  in the installation to learn about porting your servlets forward.
  Don't worry.  It's easy.

* The new `raco demodularize' tool collapses a module's dependencies
  into a single module comprising the whole program.  This
  transformation currently provides no performance improvement, but
  is the basis for cross-module optimization and dead-code
  elimination tools to come.  The transformation is currently useful
  for static analysis of whole Racket programs.

* The picturing-programs teachpack, formerly installed via PLaneT,
  is now bundled with the standard distribution.  Use the teachpack
  with `(require picturing-programs)' instead of `(require
  installed-teachpacks/picturing-programs)'.  The old PLaneT-based
  installation procedure still works, but it now merely installs a
  stub that invokes the bundled version.

* Slideshow picts, `racket/draw' bitmaps, and images created with
  `2htdp/image' can now be used directly in Scribble documents.
  More generally, the new `file/convertible' protocol enables any
  value that is convertible to a PNG and/or PDF stream to be used as
  an image in a Scribble document.

* The Same game sports a new look and an improved scoring system.
  (The current known high score is 12,429; can you beat that?)
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-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                    http://barzilay.org/                   Maze is Life!