Download Racket 7.5

Racket is a development language with which other development languages ​​can be developed. In addition, you can simply develop in Racket itself. It was previously known as PLT Scheme and comes from the Lisp-Scheme family. For the background we refer to the manifesto, written under the direction of Matthias Felleisen. The developers have released version 7.5 of Racket, with the following announcement:

Release Announcement for Version 7.5

• Almost all of Racket version 7.5 is distributed under a new, less-restrictive license: either the Apache 2.0 license or the MIT license. See https://blog.racket-lang.org/2019/11/completing-racket-s-relicensing-effort.html for more details.
• Racket CS remains “beta” quality for the v7.5 release, but its compatibility and performance continue to improve. We expect that it will be ready for production use by the next release. We encourage you to check how well the v7.5 CS release works for your programs, and help push the project forward by reporting any problems that you find.
• The Web Server provides a standard JSON MIME type, including a response / jsexpr form for HTTP responses bearing JSON.
• GNU MPFR operations run about 3x faster.
• Typed Racket supports definitions of new struct type properties and type checks uses of existing struct type properties in struct definitions. Previously, these uses were ignored by the type checker, so type errors there may have been hidden.
• The performance bug in v7.4’s big-bang has been repaired.
• DrRacket supports Dark Mode for interface elements.
• Plot can display parametric 3d surfaces.
• Redex supports modeless judgment forms.
• MacOS 10.15 (Catalina) includes a new requirement that executables be “notarized”, to give Apple the ability to prevent certain kinds of malware. In this release, all of the disk images (.dmg’s) are notarized, along with the applications that they contain (.app’s). Many users may not notice any difference, but two groups of Catalina users will be affected: those that use the “racket” binary directly, and those that download the “.tgz” bundles. In both cases, the operating system is likely to inform you that the given executable is not trusted, or that the developer can’t be verified. Fortunately, both groups of users are probably also running commands at in a shell, and the solution for both groups is the same: you can disable the quarantine flag using the `xattr` command, eg
  xattr -d com.apple.quarantine / path / to / racket
  TL; DR: Everything is fine. Read this note again if you run into problems.

The following people contributed to this release:
Alex Knauth, Alexander Shopov, Alexis King, Ayman Osman, Ben Greenman, Bert De Ketelaere, Bogdan Popa, Caleb Allen, Chuan Wei Foo, David Florness, Diego A. Mundo, Dominik Pantůček, Fred Fu, Geoffrey Knauth, Gregory Cooper, Gustavo Massaccesi, James Bornholt, Jay McCarthy, Jens Axel Søgaard, Jesse A. Tov, Jesse Alama, John Clements, Jon Zeppieri, Leo Uino, Luke Nelson, Matthew Flatt, Matthias Felleisen, Max New, Mike Sperber, Nick Thompson, Noah WM, Paulo Matos, Philip McGrath, Robby Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Shu-Hung You, Sorawee Porncharoenwase, Stephen Chang, Thomas Dickerson, and William J. Bowman