Racket v9.3

posted by Stephen De Gabrielle and John Clements

We are pleased to announce Racket v9.3 is now available from https://download.racket-lang.org/.

As of this release:

• The raco setup command can generate markdown documentation, using the --doc-markdown option.
• The "#lang" teaching languages (BSL, …, ISL+; plus DeinProgram) have reached parity with the ones chosen using the Language dialog, and are the recommended choice.
• DrRacket’s background expansion disables errortrace annotations, for faster syntax checking.
• The raco pkg install command includes new options that provide more install-time configuration flexibility: --adjacent-deps, --destdir, and --attach, and a refined --skip-installed.
• The ffi/unsafe/runtime-lib library provides a define-runtime-lib mechanism similar to define-runtime-path, allowing location of libraries located relative to a source file.
• The prompt-tag/c contract generator no longer performs checking on call/cc when the #:call/cc option is not present.
• The impersonate-prompt-tag function takes an additional argument that allows checking and update of results for composable continuations.
• The error-syntax->srcloc-handler parameter provides control over the mapping from syntactic forms to source locations for error handling.
• Uses of ([tcp-listen](https://docs.racket-lang.org/reference/tcp.html#%28def._%28%28lib._racket%2Ftcp..rkt%29._tcp-listen%29%29) 0) will retry when it fails with “address in use”.
• The racket/base module requires fewer internal modules and instantiations.
• The file/zip package provides a new mechanism for greatly increased control over zip file generation, allowing in-memory file sources and per-file compression control.

Thank you

The following people contributed to this release:

Alex Knauth, Alexander Shopov, Aris Spathis, Bert De Ketelaere, Bob Burger, Caleb Mazalevskis, Cameron Moy, Geoffrey J. Teale, Gustavo Massaccesi, Hannes Braun, Jade Sailor, Jason Hemann, Jens Axel Søgaard, John Clements, Jordan Johnson, Matthew Flatt, Matthias Felleisen, Mike Sperber, Nathan Dykman, Noah Ma, Philip McGrath, Robby Findler, Romeo Ahmed, Sam Tobin-Hochstadt, Shu-Hung You, Stefan Schwarzer, Stephen De Gabrielle, and Wing Hei Chan.

Racket is a community developed open source project and we welcome new contributors. See racket/README.md to learn how you can be a part of this amazing project.

Feedback Welcome

Questions and discussion welcome at the Racket community on Discourse or Discord.

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Racket - the Language-Oriented Programming Language - version 9.3 is now available from https://download.racket-lang.org

See https://blog.racket-lang.org/2026/08/racket-v9-3.html for the release announcement and highlights.