Release highlights

1.19.0 15 Jan 2026

• Compiler flags with values compiler
• Execution contexts in final preview including new Sync primitives stdlib/runtime
• Introduce Time::Instant and adjust behaviour of monotonic clocks stdlib/time
• Process spawning refactor and safer exec handling stdlib/process

1.18.0 14 Oct 2025

• Deprecation annotations on types and parameters lang/annotations
• Support for LLVM 22 stdlib/llvm

1.17.0 16 Jul 2025

• Event loop decides blocking mode when creating file descriptors stdlib/system
• New command: crystal tool macro_code_coverage compiler/tools
• Support for LLVM 21 stdlib/llvm

1.16.0 09 Apr 2025

• New algorithm for File.match? fixes implementation bugs stdlib/system
• Suffixes ? and ! for parameter names are deprecated lang
• Preview for execution contexts stdlib/runtime
• :showdoc: primitive for inclusion in API docs compiler/docs
• Support for LLVM 20 stdlib/llvm

1.15.0 09 Jan 2025

• Constants can start with any upper- or titlecase letter lang
• Lifetime eventloop integrates directly with system selector stdlib/runtime
• Indirect branch tracking compiler/codegen
• MinGW-W64 and MSYS2 as alternative toolchains on Windows platform/windows
• Process::Status more portable stdlib/system
• Pending formatter changes enable by default compiler/formatter

1.14.0 09 Oct 2024

• XML::Error.errors fails to compile to prevent error leaks stdlib/xml
• Platform support for aarch64-windows-msvc platform/windows
• Compiler can execute external programs as subcommands compiler/cli
• Support for LLVM 19.1 stdlib/llvm

1.13.0 09 Jul 2024

• OpenSSL now uses the library default configuration stdlib/crypto
• rescue supports module types lang
• Runtime tracing with -Dtracing stdlib/runtime
• WaitGroup for waiting on concurrent fibers stdlib/concurrency
• Basic support for AVR architecture (Adrduino) platform/arduino

1.12.0 09 Apr 2024

• Process.on_terminate for portable handling termination requests stdlib/system
• LLVM 18 and deprecation of llvm_ext stdlib/llvm
• Assignment operators can receive multiple parameters and blocks lang
• Preliminary support for Solaris/Illumos platform/solaris
• New command: crystal tool flags compiler/tools
• Experimental support for ReferenceStorage to control reference allocations lang

1.11.0 08 Jan 2024

• New compiler optimization levels compiler/codegen
• New alignment primitives alignof and instance_alignof lang/primitives
• dll parameter for @[Link] annotations lang/annotations
• Macro call context accessible as @caller lang/macros
• Support for LLVM 18 allows dropping llvm_ext stdlib/llvm

1.10.0 09 Oct 2023

• Unpacking for nested block parameter with splat support lang/blocks
• New commands crystal tool dependencies and crystal tool unreachable compiler/tools

1.9.0 11 Jul 2023

• Comparison with Big* types are now nilable stdlib/numeric
• New command crystal clear_cache compiler/tools
• Support for LLVM 16 stdlib/llvm

1.8.0 14 Apr 2023

• PCRE2 default regex engine stdlib/text
• Regex literals expect PCRE2 syntax lang/literals
• Support for LLVM 15 with opaque pointers stdlib/llvm
• x86_64-linux-musl promoted to tier 1 platform/linux
• New target aarch64-linux-android platform/android
• New portable APIs for process-lifecycle events stdlib/system

1.7.0 09 Jan 2023

• Preview for PCRE2 stdlib/text

1.6.0 06 Oct 2022

• Improved overload ordering lang/types

1.5.0 06 Jul 2022

• Types of instance variables propagate to method parameter restrictions lang/types
• Annotations on method parameters lang/annotations

1.4.0 06 Apr 2022

• Experimental support for WebAssembly (wasm32-wasi) platform/wasm
• Improved type inference for instance and class variables lang/types
• Support for LLVM 14 stdlib/llvm

1.3.0 06 Jan 2022

• Autocasting for primitive numeric values lang/numeric
• 128-bit number literals lang/numeric
• Interpreter preview merged compiler/interpreter
• Windows packages available platform/windows
• Experimental Syscall API stdlib/system
• Splat support in multi-assign lang

1.2.0 14 Oct 2021

• aarch64-darwin promotes to tier 2, i386-linux-gnu demoted to tier 2 platform
• Dropped disfunct ThinLTO support compiler/linking
• Render markdown with markd shard compiler/docs
• Support for 128-bit integers stdlib/numeric
• Indexable::Mutable(T) module stdlib/collections

1.1.0 16 Jul 2021

• Splat embedding in enumerable literals and type definitions lang
• while are typed as a union of all break expressions plus Nil lang
• New @top_level macro variable lang/macros
• Segfault handler implemented in Crystal, no libcrystal anymore stdlib/runtime

1.0.0 22 Mar 2021

• Removed deprecated features stdlib
• Type-safe tuple accessors with literal ranges lang/tuples
• New fine-grained rounding modes stdlib/numeric