# Crystal A language for humans and computers This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## Crystal 1.21.0 is released! DevFeed: [Crystal 1.21.0 is released!]() Original publisher: [Read original article]() Author: Johannes Müller Published: 2026-07-16T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [Concurrency](), [Concurrent Programming]() Tags: [bug-fixes](), [changelog](), [new-features](), [release]() ### AI overview Crystal 1.21.0 introduces execution contexts enabled by default, string array literals with interpolation, split manpages infrastructure, and other language, compiler, and standard-library changes. The release includes bug fixes and 161 changes from 21 contributors. ### Source excerpt We are announcing a new Crystal release 1.21.0 with several new features and bug fixes. ## Releasing Execution Contexts DevFeed: [Releasing Execution Contexts]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-07-12T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [Concurrency](), [Concurrent Programming](), [context](), [cpu]() Tags: [concurrent](), [cpu](), [kotlin](), [main-thread](), [multithreading](), [parallelism](), [threads]() ### AI overview Crystal is introducing Execution Contexts, an interface for orchestrating fibers across one or more threads. The article describes concurrent and parallel contexts, configurable parallelism, and execution across CPU cores while preserving a single-threaded default. ### Source excerpt Two and a half years ago, with the invaluable support from 84codes, we re-examined the multithreading model inherited from Crystal 0.28 (preview MT). ## Crystal 1.20.3 is released! DevFeed: [Crystal 1.20.3 is released!]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-07-02T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [Vulnerabilities](), [YAML](), [Parser]() Tags: [parsing](), [release](), [releases](), [security](), [security-vulnerabilities](), [yaml]() ### AI overview Crystal 1.20.3 is a release that fixes two security vulnerabilities in its YAML parsers. The fixes address excessive nesting that could cause stack overflows and excessive YAML alias expansion associated with billion laughs attacks. The article recommends upgrading when processing YAML files from unknown origins. ### Source excerpt We are announcing a new Crystal release 1.20.3 with fixes for two security vulnerabilities in the YAML parsers. We recommend upgrading as soon as possible if your application processes YAML files from unknown origins. ## Post Mortem: HTTP Request Smuggling Vulnerability DevFeed: [Post Mortem: HTTP Request Smuggling Vulnerability]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-05-26T00:00:00Z Content type: article Language: en Sources: [Crystal]() Topics: [Post Mortem](), [vulnerability](), [Crystal](), [HTTP](), [Security](), [Exploit]() Tags: [2026](), [access-control](), [http](), [post-mortem](), [rate-limiting](), [security](), [server](), [vulnerability]() ### AI overview This post-mortem describes an HTTP request smuggling vulnerability in Crystal's HTTP server. The parser mishandled requests containing conflicting framing headers, allowing request injection between a reverse proxy and a Crystal server under specific proxy conditions. The issue was patched in Crystal 1.20.0 and 1.19.2. ### Source excerpt On 12 April 2026, we received a vulnerability report regarding an HTTP request smuggling vulnerability in HTTP::Server. ## Crystal 1.20.2 is released! DevFeed: [Crystal 1.20.2 is released!]() Original publisher: [Read original article]() Author: Johannes Müller Published: 2026-05-15T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [bug](), [changelog]() Tags: [bug-fixes](), [regression](), [release](), [release-notes](), [releases]() ### AI overview Crystal 1.20.2 is a patch release that fixes two regressions, including an issue that could eventually cause loss of randomness in the 1.20 release branch. Pre-built packages are available through GitHub Releases and official distribution channels. ### Source excerpt We are announcing a new Crystal release 1.20.2 with a couple of regressions fixed. ## Crystal 1.20.1 is released! DevFeed: [Crystal 1.20.1 is released!]() Original publisher: [Read original article]() Author: Johannes Müller Published: 2026-04-29T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [changelog](), [Kernel]() Tags: [github](), [installation](), [regression](), [release](), [release-notes](), [releases](), [tls]() ### AI overview Crystal 1.20.1 is a patch release that fixes regressions from Crystal 1.20.0. It includes nine changes by two contributors, and pre-built packages are available through GitHub Releases and official distribution channels. Kernel TLS is disabled by default because of production issues, while a randomness-related regression was also fixed. ### Source excerpt We are announcing a new Crystal release 1.20.1 with a couple of regressions fixed. ## Crystal 1.19.2 is released! DevFeed: [Crystal 1.19.2 is released!]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-04-27T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [changelog](), [Development](), [HTTP]() Tags: [changelog](), [contributors](), [github](), [installation](), [language](), [regression](), [release](), [releases](), [support]() ### AI overview Crystal 1.19.2 is a patch release that fixes two regressions. It includes three changes since Crystal 1.19.1, updates HTTP parsing behavior to reject requests containing both conflicting headers, and fixes a regression that could eventually cause loss of randomness. Pre-built packages are available through GitHub Releases and official distribution channels. ### Source excerpt We are announcing a new Crystal release 1.19.2 with two regressions fixed. ## Crystal 1.20.0 is released! DevFeed: [Crystal 1.20.0 is released!]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-04-16T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [releases](), [Compiler](), [Processes](), [HTTP]() Tags: [bug-fixes](), [compiler](), [features](), [http](), [release]() ### AI overview Crystal 1.20.0 introduces new annotation support, preview APIs for spawning processes and capturing output, an event loop implementation, compiler changes, and bug fixes. The release includes 161 changes from 21 contributors and is not expected to introduce breaking changes. ### Source excerpt We are announcing a new Crystal release 1.20.0 with several new features and bug fixes. ## Official Linux ARM64 builds DevFeed: [Official Linux ARM64 builds]() Original publisher: [Read original article]() Author: Julien Portalier Published: 2026-04-07T00:00:00Z Content type: release Language: en Sources: [Crystal]() Topics: [Crystal](), [Linux](), [Arm](), [Compiler](), [Docker](), [GitHub](), [snap](), [Ubuntu]() Tags: [arm](), [compiler](), [docker](), [github](), [linux](), [release](), [snap](), [ubuntu]() ### AI overview Crystal now provides official Linux ARM64 builds for nightly versions and the 1.19 release. The builds are distributed through release tarballs, Docker images, Snap, and the install-crystal GitHub action, with Ubuntu ARM runners supported. ### Source excerpt This has been a long awaited feature: how to run Crystal on ARM64 CPUs? ## Crystal talk at FOSDEM 2026 DevFeed: [Crystal talk at FOSDEM 2026]() Original publisher: [Read original article]() Author: Johannes Müller Published: 2026-01-23T00:00:00Z Content type: news Language: en Sources: [Crystal]() Topics: [Crystal](), [FOSDEM]() Tags: [2026](), [declarative](), [fosdem](), [introduction](), [merch](), [talk](), [update](), [video]() ### AI overview The author announces a talk about Crystal at FOSDEM 2026 in Brussels, titled "Crystal: A language for humans and computers." The talk introduces Crystal concepts, and a recording is available for those who cannot attend. ### Source excerpt I'm giving a talk about Crystal at FOSDEM 2026 in Brussels: Crystal: A language for humans and computers. It's in the Declarative and Minimalistic Computing track, on Sunday, 1 February 2026 at 09:00 in room UB4.136.