Release Announcement for Version 7.9

Racket v7.9

* Racket CS may become the default Racket implementation in the next
  release. If, between this release and the next, no bugs are discovered
  in Racket CS that are more serious than those typically discovered in
  Racket BC, then Racket CS will become the default for the next
  release. (Serious Racket CS bugs were found since the v7.8 release,
  but they're ever fewer and farther between.)

* Various improvements to Check Syntax arrows and
  renaming, thanks to Sorawee Porncharoenwase

* Full support for struct type properties in Typed Racket, developed by
  Fred Fu.

* Racket CS now supports parallel garbage collection, along with
  improvements for place-local-allocation and incremental promotion.

* Unix platforms now use the XDG filesystem conventions for the
  locations of per-user configuration and library files by default, but
  legacy paths are still used where they exist already.

* Scribble improvements by Sorawee Porncharoenwase, William Bowman, and
  Shu-Hung You.

* Improvements to the plot library from Alex Harsányi and Bert De

* The `datum` form from `syntax/datum` works with syntax pattern
  variables and `syntax-parse` attributes.

* Unicode input works with recent versions of libedit in addition
  to libreadline. On Mac OS, a compatible version of libedit is
  included with Racket.

The following people contributed to this release:

5pyd3r, A. Green, Adam Michael, Alex Bartholomew, Alex Harsányi, Alex
Knauth, Alexander B. McLin, Alexander Shopov, Alexis King, Andrew
Mauer-Oats, Andy Keep, Ayman Osman, Barak A. Pearlmutter, Ben Greenman,
Bert De Ketelaere, Bob Burger, Bodie Solomon, Bogdan Popa, Bruce
Mitchener, Chris Frisz, Christian Häggström, Cullen Jennings, Daniel
Brunner, DeathKing, Dionna Amalie Glaze, Dominik Pantůček, Evan Minsk,
Fred Fu, Gavin Whelan, Graham Watt, Griffin Byatt, Gustavo Massaccesi,
Göran Weinholt, Jack Firth, Jamie Taylor, Jason Felice, Jason Hemann,
Jasper Pilgrim, Jay McCarthy, Jesse Alama, Jin-Ho King, John Clements,
Jon Zeppieri, Juan Francisco Cantero Hurtado, Jéssica Milaré, Jörgen
Brandt, Laurent Orseau, Leo Uino, Matthew D. Miller, Matthew Flatt,
Matthias Felleisen, Michael Lenaghan, Mike Sperber, Mohamed Akram, Neal
Alexander, Nick Fitzgerald, Oscar Waddell, Paulo Matos, Pavel Panchekha,
Peter Klein, Philip McGrath, Quentin Dufour, R. Kent Dybvig, Robby
Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Shu-Hung You, Sorawee
Porncharoenwase, Stephen Chang, Stephen De Gabrielle, Steven Watson,
Taekyung, Ted Lemon, Thorsten Blum, Virgil Hou, William J. Bowman,
combinatorylogic, deeglaze, evdubs, john, tokomikea, xxyzz, yjqww6, 陈梓
立, and 靈