# Racket v8.18 — Racket v8.18

- Product: Racket (https://whatsnew.fyi/product/racket)
- Vendor: Racket
- Date: 2025-08-22
- Version: v8.18
- Original notes: https://github.com/racket/racket/releases/tag/v8.18
- Permalink: https://whatsnew.fyi/product/racket/releases/v8.18

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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- **changed** — The racket-lang.org website no longer distributes Racket BC bundles, but includes pre-built bundles for AArch64 and 32-bit ARMv6 VFP ARM linux
- **added** — XML structures are serializable
- **changed** — Scribble's HTML generation conforms better to modern standards
- **changed** — Racket uses Unicode 16.0 for character and string operations
- **changed** — The redex-check default generation strategy always uses random generation to supplement the enumerator
- **added** — DrRacket supports shift-tab to go backward to previous indentation positions
- **added** — The macro stepper supports the string-constants library for internationalization
- **added** — The struct form supports #:properties prop-list-expr for attaching multiple property values to a structure type
- **changed** — Build-system improvements support containers registered at Docker Hub to build for all platforms and Unix-style builds for Mac OS in the style of MacPorts
- **fixed** — The expt function produces a more accurate result when its first argument is a flonum and its second argument is an exact integer that has no equivalent flonum representation
- **fixed** — TCP ports use SO_KEEPALIVE correctly
- **added** — Unsafe code can use uninterruptible mode instead of atomic mode to allow futures to run concurrently while preventing interruptions from other threads
- **added** — The net/imap library supports IMAP's move operation

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- The racket-lang.org website no longer distributes Racket BC bundles,
  but it includes pre-built bundles for two flavors of ARM linux,
  AArch64 and 32-bit ARMv6 VFP.
- XML structures are serializable.
- Scribble's HTML generation conforms better to modern standards.
- Racket uses Unicode 16.0 for character and string operations.
- The `redex-check` default generation strategy always uses random
  generation to supplement the enumerator.
- DrRacket supports the use of shift-tab to go backward to previous
  indentation positions.
- The macro stepper supports the string-constants library, allowing
  internationalization of the stepper itself.
- The `struct` form supports `#:properties prop-list-expr`, making it
  more convenient to attach multiple property values to a structure
  type.
- Build-system improvements support containers registered at Docker
  Hub to build for all platforms that have downloads from the main
  Racket download site; improvements also support Unix-style builds
  for Mac OS in the style of MacPorts.
- The `expt` function produces a more accurate result when its first
  argument is a flonum and its second argument is an exact integer
  that has no equivalent flonum representation than it did in prior
  versions.
- TCP ports use `SO_KEEPALIVE` correctly.
- Unsafe code can use “uninterruptible mode” instead of “atomic mode”
  to allow futures to run concurrently while preventing interruptions
  from other threads.
- The `net/imap` library supports IMAP's `move` operation.
- There are many other repairs and documentation improvements!

The following people contributed to this release:

Bob Burger, Bogdan Popa, Brad Lucier, Carl Gay, Chloé Vulquin, D.
Ben Knoble, Gustavo Massaccesi, Jacqueline Firth, Jade Sailor,
Jarhmander, Jason Hemann, Jens Axel Søgaard, Joel Dueck, John
Clements, jyn, Jörgen Brandt, Mao Yifu, Marc Nieper-Wißkirchen,
Matthew Flatt, Matthias Felleisen, Mike Sperber, Noah Ma,
paralogismos, Pavel Panchekha, Philip McGrath, Robby Findler, Ryan
Culpepper, Sam Tobin-Hochstadt, Shalok Shalom, Stephen De Gabrielle,
Steve Byan, Vincent Lee, Wing Hei Chan, and ZC Findler.

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