Racket v5.93

Version 5.93 repairs a few problems with the recent v5.92 release (in
preparation for a v6.0 release):

 * fixed a low-level concurrency problem with the GUI library for Mac
   OS X, which especially affected 32-bit builds;

 * fixed GRacket-based launchers (such as `drracket`) in a Unix-style
   installation;

 * expanded the list of recognized OpenSSL library versions;

 * fixed small CSS problems and inconsistencies (relative to v5.3.6) in
   the new Scribble style as used by the Racket documentation; and

 * added the version number back to the "racket" directory within the
   source distribution bundle.

Racket v5.92

Racket 5.92 has a new package system, including a catalog of
hundreds of already-available packages. Please visit

  http://pkgs.racket-lang.org/

for an overview of the packages.

Recent releases included the "beta" versions of the package system.
Racket version 5.92 incorporates many improvements suggested by these
preliminary experiences:

 * A package is treated as a single collection by default, so it is
   even easier to use a Github repository as a package. Get started
   quickly:
     http://docs.racket-lang.org/pkg/getting-started.html

 * DrRacket includes a new package manager GUI, available via the
   File|Package Manager ... menu item. The GUI is also available
   as a stand-alone program via the "gui-pkg-manager" package.

 * The main Racket distribution has been separated into about 200
   packages. The Racket installer combines the core system with
   bundled versions of these packages.

   Alternatively, you may now install a Minimal Racket distribution
   --- which is about 1/10 the size of the main distribution --- and
   add only those packages that you need.

 * Package installation supports pre-built packages that include
   compiled byte code and rendered documentation, meaning packages can
   be installed quickly when built versions are available. All
   packages in the main distribution are available in pre-built form.

Further improvements are in the works, notably including package
documentation on the package-catalog web site.

COMPATIBILITY NOTE: PLaneT, the previous Racket package system, will
remain in place for the foreseeable future, but we expect all package
work to shift to the new system.

Beyond the package system, this release brings a number of other
changes:

 * Racket's HTML documentation has a new and improved look, thanks to
   Matthew Butterick.

 * The documentation includes a style guide, "How to Program Racket"
   http://docs.racket-lang.org/style/

 * Racket's JIT compiler supports the ARM architecture.

 * Racket supports the Mac's Retina display mode.

 * The performance of the Typed Racket compiler improved by 50% on
   some typed programs; e.g., see http://bit.ly/1d0Ye4z

 * The profiler provides a new mode that uses the errortrace library
   to produce fine-grained profiles.

 * A new contract profiler reports how much time programs spend
   checking contracts, and which contracts are most expensive.

 * The math/flonum library exports fast 105-bit precision operations.

 * Check Syntax handles generated identifiers, especially those
   introduced by struct (e.g. field selectors) and Redex (e.g., e_1,
   e_2)

 * 2htdp/batch-io includes functions for dealing with html/xml in
   files and web sites as X-expressions plus conveniences for
   web-based graph traversals.

 * The `gen:set' generic interface extends set operations to work on
   user-defined types that implement set methods, as well as on other
   set-like built-in types, such as lists.

 * Picts support conversion to SVG format.

 * Under unix, Racket provides desktop entries (.desktop files) for
   its graphical executables.

Racket v5.3.6

Racket v5.3.6 is a bug-fix release.  It eliminates errors from v5.3.5
that people have found over the summer.

Racket v5.3.5

This is a special-purpose release to match the arrival of "Realm of
Racket" in bookstores.  Racket v.5.3.5 adds a single `realm'
collection to the v5.3.4 release.  The new collection contains the
source code that readers of Realm may wish to use for experiments.

Racket v5.3.4

* Extflonums (80-bit floating-point numbers) are supported on some
  x86/x86_64 platforms -- including Windows, and including platforms
  where Racket is compiled to use SSE instructions for flonum
  arithmetic.  Thanks to Michael Filonenko.

* OS X: DrRacket and all of the other apps are now signed with an
  official key.

* Tally Maze: a new game based an enumeration of 2d mazes.

* The Optimization Coach, a DrRacket plugin, has been moved from the
  Racket distribution to the Racket package repository.  Install it
  with: raco pkg install optimization-coach

* Redex: `define-union-language' now merges productions when
  languages define the same nonterminals.  Thanks to William Bowman.

* The `srfi/19' library is now compatible with the date structure
  type exported by `racket/base'.

Racket v5.3.3

This is a bug-fix release to address a flaw in DrRacket v5.3.2
concerning interactions between the contour window and the syntax
coloring.

Racket v5.3.2

Core Libraries:

* The new `math' library provides functions and data structures for
  working with numbers and collections of numbers.  Functions include
  non-elementary (such as gamma, zeta, Lambert's W), number-theoretic
  (factorization, modular arithmetic), linear algebra (arithmetic,
  decompositions), and statistical (expected values, order statistics,
  binning).  Data structures include arbitrary-precision bigfloats,
  probability distributions, and multidimensional arrays.

* The new `file/untar', `file/untgz', and `file/unzip' libraries support
  unpacking widely used archive formats.

* The new `lazy-require' form allows programs to delay the loading and
  instantiation of helper modules until they are needed.

* The new `data/bit-vector' library provides an implementation of bit
  vectors (a mutable sequence of booleans) supporting popcount.

* The `racket/generic' library allows the specification of default
  method implementations for core datatypes.

* The `openssl' library can verify hostnames and use the operating
  system's certificate store to verify certificates.

Package System:

* A new package system is in beta release.  This system will become
  Planet's successor.  It differs significantly from the latter.  For
  details, please read the documentation at
  http://docs.racket-lang.org/planet2/ and list your packages on the new
  index at https://pkg.racket-lang.org/.

* The `raco test' command supports testing by collection and package, in
  addition to by directory and file, with the "-c" and "-p" options.

Teaching Libraries:

* batch-io: the read and write functions work on Unix-style standard
  input and output.

DrRacket:

* DrRacket's GUI is more responsive.

* The automatic parenthesis insertion mode is improved.

Scribble:

* Scribble renders Markdown format files via the "--markdown"
  command-line flag.  Example use case: Generate documentation hosted on
  GitHub or BitBucket.

* Documentation cross-reference information is stored in an SQLite3
  database, which means that SQLite3 is required for building Racket
  documentation on Unix/Linux machines (but SQLite3 is included in
  Racket distributions for Windows and Mac OS X).

  Using a database for cross-reference information significantly reduces
  the initial footprint of DrRacket, since DrRacket no longer needs to
  load all cross-reference information.

Typed Racket:

* Typed Racket programs can require `plot/typed' to draw plots.  List-
  and vector-accepting functions accept general sequences.

* Typed Racket supports Racket's delimited continuation and continuation
  mark operators.

Redex:

* Added more support for `define-judgment-form', including random
  generation for well-formed judgments and visualization of judgments.

Deprecation:

The following have been removed in this release:

* the `planet' command-line tool; use `raco planet' instead.

The following has been deprecated and will be removed in the August 2013
release:

* the `mzlib/class100' library; use `racket/class' instead.

Racket v5.3.1

Racket:

* The `case' form dispatches on characters, fixnums, symbols, and
  keywords in logarithmic time.  (Thanks to Jon Zeppieri.)

* The new `racket/format' library provides new and improved
  string-formatting functions.

* Logging tools include improved filtering support based on the name
  of a logger.  A new `define-logger' form simplifies the use of
  named loggers.  Forms such as `log-debug' now support string
  formatting.

* The `for' forms now support `#:break' and `#:final' clauses.

* The new PLTCOMPILEDROOTS environment variable configures the
  search path for compiled bytecode.

DrRacket:

* Check Syntax now summarizes the documentation (i.e., the blue
  boxes) for the identifier at the insertion point in the top-right
  corner of the definitions window.

* Check Syntax now runs continuously for programs that declare their
  language within the source.  This mode has been available for
  several of the past releases, but now enabled by default.

* DrRacket can spell-check string constants (enable this in the Edit
  menu).

Typed Racket:

* Typed Racket interprets the Any type as a different contract.
  This may signal dynamic errors in some existing mixed
  typed/untyped programs.  The normal fix is to replace a use of Any
  with a more specific types.

* NaN is included in all of Typed Racket's floating-point types,
  which makes precise floating-point types easier to use.

* Typed Racket supports a `cast' operation with support for
  higher-order types.

* Typed Racket provides the `:query-type/args' and
  `:query-type/result' utilities to explore types at the REPL.

Miscellaneous:

* The `compatibility' collection provides features from Racket
  relatives, such as `defmacro' and mutable lists.  These features
  are provided to ease porting code to Racket.  Avoid them in modern
  Racket code.

* Screenshots of the widgets provided by the Racket GUI library are
  included in the documentation.  (Thanks to Diogo F. S. Ramos.)

* FrTime was ported to racket lang.  (Thanks to Patrick Mahoney.)

Deprecation:

The following has been deprecated and will be removed in the January
2013 release:

* the `planet' command-line tool; use `raco planet' instead.

The following has been deprecated and will be removed in the August
2013 release:

* the `mzlib/class100' library; use `racket/class' instead.

Racket v5.3

* Submodules are nested module declarations that can be loaded and
  run independently from the enclosing module.  For an overview of
  submodules, see

    http://blog.racket-lang.org/2012/06/submodules.html

* The futures visualizer is a graphical profiling tool for parallel
  programs using futures.  The tool shows a detailed execution
  timeline depicting the migration of futures between threads, and
  gives detailed information about each runtime synchronization that
  occurred during program execution.  In addition, `would-be-future'
  is a special type of future that always executes sequentially and
  records all potential barricades a regular future would encounter.

* Optimization Coach (formerly Performance Report) reports
  information about Racket's inlining optimizations.  Optimization
  Coach can be launched in any language through the View menu.

* The new `images/flomap' library defines floating-point bitmaps and
  fast image processing operations on them.  It is written in Typed
  Racket, so Typed Racket code may use it without the cost of
  contract checks.

* The new `json' library supports parsing and generating JSON.
  (Originally based on Dave Herman's planet library.)

* `racket/string' is extended with a set of simplified string
  manipulation functions that are more convenient than using
  regexps.  `regexp-match*' and friends can now be used with new
  keyword arguments to return specific matched regexp group/s and
  gaps between matches.

* The new `racket/generic' library allows generic function
  definitions, which dispatch to methods added to a structure type
  via the new `#:methods' keyword.

* The `class' form supports declaring a method abstract.  An
  abstract method prevents a class from being instantiated unless it
  is overridden.

* The contract library comes with support for interfaces, generics,
  prompts, continuation-marks, and structs.

* Most error messages use a new multi-line format that is more
  consistent with contract errors and accommodates more information.

* Typed Racket supports function definitions with keyword arguments;
  the startup time of Typed Racket programs has been sharply
  reduced.

* The new `ffi/com' library replaces MysterX; a compatibility
  `mysterx' library remains, but without ActiveX support.  The new
  `ffi/unsafe/com' library offers a more primitive and direct way to
  use COM classes and methods.

* There is now a very complete completion code for zsh.  It is not
  included in the distribution though; get it at http://goo.gl/DU8JK
  (This script and the bash completions will be included in the
  standard installers in future versions.)

--- DEPRECATION ----------------------------------------------------

Effective this release:

  - The `tex2page' and `combinator-parser' libraries have been moved
    from the Racket distribution to PLaneT:

     (require (planet plt/tex2page))
     (require (planet plt/combinator-parser))

The following has been deprecated and will be removed in the
January 2013 release:

  - the `planet' command-line tool; use `raco planet' instead.

The following has been deprecated and will be removed in the
August 2013 release:

  - the `mzlib/class100' library; use `racket/class' instead.

Racket v5.2.1

* Performance improvements include the use of epoll()/kqueue() instead
  of select() for the Racket thread scheduler, cross-module inlining of
  small functions, and the use of SSE instead of x87 for JIT-compiled
  floating-point operations on platforms where SSE is always available
  (including x86_64 platforms).  A related change is the interning of
  literal numbers, strings, byte strings, characters, and regexps that
  appear in code and syntax objects.

* DrRacket uses a set of composable ray-traced icons available from the
  new `images' library collection.

* Typed Racket's `typecheck-fail' form allows macro creators to
  customize the error messages that Typed Racket produces.  This is
  especially useful when creating pattern matching macros.

* The performance of Redex's matcher has been substantially improved;
  depending on the model you should see improvements between 2x and 50x
  in the time it takes to reduce terms.

* Plots look nicer and are more correct at very small and very large
  scales.  New features include customizable dual axis ticks and
  transforms (e.g., log axes, date and currency ticks, axis interval
  collapse and stretch), stacked histograms, and 3D vector fields.  The
  legacy `fit' function and libfit have been removed.

* The `2htdp/universe' library's `big-bang' form supports an
  experimental game pad key handler.

* The `db' library now supports nested transactions and PostgreSQL
  arrays.  Bugs involving MySQL authentication and memory corruption in
  the SQLite bindings have been fixed.

* The Macro Stepper tool in DrRacket no longer executes a program after
  expanding it.

* In the DMdA teaching languages, infinite recursive signatures
  ("streams", for example) with no intervening `mixed' are now
  supported, and the signatures of record definitions without fields now
  have generators for use with `property'.

* MysterX's ActiveX support is deprecated and will be removed in the
  next release.  MysterX's core COM functionality will become deprecated
  in the next release, but COM functionality will be supported for the
  foreseeable future as a compatibility layer over a forthcoming
  `ffi/com' library.