Announce: Rakudo Star - a useful, usable, "early adopter" distribution of Perl 6

On behalf of the Rakudo and Perl 6 development teams, I'm happy to
announce the September 2012 release of "Rakudo Star", a useful and
usable distribution of Perl 6.  The tarball for the September 2012
release is available from <http://github.com/rakudo/star/downloads>.
A Windows .MSI version of Rakudo star will usually appear in
the downloads area shortly after the tarball release.

In the Perl 6 world, we make a distinction between the language 
("Perl 6") and specific implementations of the language such as
"Rakudo Perl".  This Star release includes release 2012.09.1 [0] of the
Rakudo Perl 6 compiler [1], version 4.6.0 of the Parrot Virtual
Machine [2], and various modules, documentation, and other
resources collected from the Perl 6 community.

Some of the new features added to this release include:

* Basic macro support!

* Support for Perl 5 (m:P5/.../) regex syntax!

* Indirect type names in routine and type declarations are supported.

* We support the "is export" trait on constant declarations.

* The "is hidden" and base traits are supported.

* Str.wordcase, is-prime, and expmod are implemented.

* Compilation is slightly faster than before.

* Tie-breaking with constraints selects the first matching
  constraint rather than demanding mutual exclusion.

* Smart matching against Signature literals, and binding to Signatures
  in declarators.

This release also contains a range of bug fixes, improvements to error
reporting and better failure modes. More exceptions are thrown as typed
exceptions, and more meta-model errors have been fixed to properly
report line numbers.

The following features have been deprecated or modified from previous
releases due to changes in the Perl 6 specification, and are being removed
or changed as follows:

* Iterable is now a role instead of a class, and no longer inherits 
  from Cool.

* Parameters preceded by a | or \ can no longer have a sigil.

* IO::Path.dir (which returns the directory part of the path) has been
  renamed to IO::Path.directory.  IO::Path.dir will be removed or
  re-purposed.

* The Str.ucfirst builtin is deprecated; it will be replaced by Str.tc.

* The (experimental) LAZY statement prefix will soon be removed.

* Leading whitespace in rules and under :sigspace will no longer be
  converted to <.ws> .  For existing regexes that expect this conversion,
  add a <?> in front of leading whitespace to make it meta again.

* The ?-quantifier on captures in regexes currently binds the capture
  slot to a List containing either zero or one Match objects; i.e., it
  is equivalent to "** 0..1".  In the future, the ?-quantifier will
  bind the slot directly to a captured Match or to Nil.  Existing code
  can manage the transition by changing existing ?-quantifiers to
  use "** 0..1", which will continue to return a List of matches.

There are some key features of Perl 6 that Rakudo Star does not
yet handle appropriately, although they will appear in upcoming
releases.  Some of the not-quite-there features include:

  * advanced macros
  * threads and concurrency
  * Unicode strings at levels other than codepoints
  * interactive readline that understands Unicode
  * non-blocking I/O
  * much of Synopsis 9

There is an online resource at http://perl6.org/compilers/features 
that lists the known implemented and missing features of Rakudo 
and other Perl 6 implementations.

In many places we've tried to make Rakudo smart enough to inform the
programmer that a given feature isn't implemented, but there are
many that we've missed.  Bug reports about missing and broken
features are welcomed at <rakudobug@perl.org>.

See http://perl6.org/ for links to much more information about 
Perl 6, including documentation, example code, tutorials, reference
materials, specification documents, and other supporting resources.
A draft of a Perl 6 book is available as <docs/UsingPerl6-draft.pdf> 
in the release tarball.

The development team thanks all of the contributors and sponsors
for making Rakudo Star possible.  If you would like to contribute,
see <http://rakudo.org/how-to-help>, ask on the perl6-compiler@perl.org
mailing list, or join us on IRC #perl6 on freenode.

[0] https://github.com/rakudo/rakudo/blob/nom/docs/announce/2012.09
[1] http://github.com/rakudo/rakudo
[2] http://parrot.org/
