# Racket v9.2 — Racket v9.2

- Product: Racket (https://whatsnew.fyi/product/racket)
- Vendor: Racket
- Date: 2026-05-28
- Version: v9.2
- Original notes: https://github.com/racket/racket/releases/tag/v9.2
- Permalink: https://whatsnew.fyi/product/racket/releases/v9.2

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **fixed** — The match form checks that non-linear patterns with ... have equal parts and rejects non-linear patterns where one use of a variable has ... and another does not
- **fixed** — Typed Racket's types for asin and acos procedures correctly handle situations where the function produces a complex number
- **added** — The #%foreign-inline core syntactic form provides unsafe access to facilities provided at the linklet layer by a Racket implementation
- **changed** — Unicode 17.0 is used for character and string operations
- **added** — Internal support for a more static ffi2 foreign interface
- **added** — The terminal-file-position function counts bytes written to ports connected to a terminal, such as stdin and stderr
- **changed** — Cross-phase persistent modules allow more types of quoted data
- **changed** — The implementations of member, memw, when, unless, let/ec, and cond are rewritten to use only racket/kernel syntax
- **added** — The impersonator-property-predicate-procedure? function identifies procedures created by make-impersonator-property
- **changed** — In Typed Racket, polymorphic struct types are printed using type arguments rather than exposing an internal representation
- **changed** — The stepper's display of numbers better matches the language settings
- **changed** — Scribble documents that do not use the Racket-manual style get an initial-scale of 1.0 instead of 0.8, but this can be configured using the initial-scale property
- **changed** — By default, margin notes appear inline for narrow displays in all styles, not just in the Racket-manual style
- **fixed** — Big-bang programs distributed as .dmg files correctly handle the close-on-stop feature

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- The `match` form checks that when non-linear patterns (patterns
  where the same variable is used multiple times) are used with `...`,
  the two parts of the matched value actually are equal. Additionally,
  match rejects non-linear patterns where one use of the variable is
  used with `...` and another is not. This repair could cause existing
  code to fail.
- Typed Racket's types for the `asin` and `acos` procedures correctly
  handle situations where the function produces a complex number,
  avoiding unsound results that were previously possible. This repair
  could cause existing code to fail at compile time.
- The `#%foreign-inline` core syntactic form provides unsafe access to
  facilities provided at the linklet layer by a Racket implementation.
  This means that any code that handles all core forms by enumeration
  will need to be updated.
- Unicode 17.0 is used for character and string operations.
- This release includes internal support for a more static "ffi2"
  foreign interface (to be used in a future package).
- The `terminal-file-position` function counts bytes written to ports
  connected to a terminal, such as `stdin` and `stderr`.
- Cross-phase persistent modules allow more types of `quote`d data.
- The implementations of `member`, `memw`, `when`, `unless`, `let/ec`,
  and `cond` are rewritten to use only `racket/kernel` syntax
- The `impersonator-property-predicate-procedure?` function identifies
  procedures created by `make-impersonator-property`.
- In Typed Racket, polymorphic struct types are printed using type
  arguments (e.g., `(Array Byte)`) rather than exposing an internal
  representation.
- The stepper's display of numbers better matches the language
  settings.
- Scribble documents that do not use the Racket-manual style get an
  `initial-scale` of 1.0, instead of the manual style's 0.8, but this
  can be configured using the `initial-scale` property.
- By default, margin notes appear inline for narrow displays in all
  styles, not just in the Racket-manual style.
- Big-bang programs distributed as .dmg files correctly handle the
  `close-on-stop` feature.
- There are many other repairs and documentation improvements!

The following people contributed to this release:

Alexander Shopov, Alexis King, Asilo, Bert De Ketelaere, Bob Burger,
Bogdan Popa, Chung-chieh Shan, François-René Rideau, Gustavo
Massaccesi, Ilya Klyuchnikov, Jade Sailor, Jamie Taylor, John
Clements, Jonathan Simpson, LS_Hower, Matthew Flatt, Matthias
Felleisen, Mike Sperber, Pavel Panchekha, Philippe Meunier, RMOlive,
Robby Findler, Roman Klochkov, Sam Tobin-Hochstadt, Shu-Hung You,
Stephen de Gabrielle, Tejas Sanap, Vincent Lee, and Wing Hei Chan.

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