You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Todd Sundsted 70bec07995
Ensure `type_vars` works for generic modules. (#9161)
3 days ago
.circleci Update distributions-script (#9242) 4 weeks ago
.github/workflows Win CI: add libxml2 and enable more specs (#9346) 1 week ago
bin CI: Use --json-config-url doc option (#9370) 1 week ago
etc Improve debugging support (#8538) 1 month ago
man Refactor Docs::Generator source link generation (#9119) 3 weeks ago
samples Regenerate implementation tool sample (#9003) 1 month ago
scripts Add version select to docs HTML 1 month ago
spec Ensure `type_vars` works for generic modules. (#9161) 3 days ago
src Ensure `type_vars` works for generic modules. (#9161) 3 days ago
.dockerignore Dockerfile now uses `make`. Fixes build after addition of LLVM extensions in c++. 4 years ago
.editorconfig Mark .editorconfig as root (#6031) 2 years ago
.gitignore Resolve the always-present Windows linker's warnings (#9307) 3 weeks ago
.travis.yml Run formatter in travis. Update /bin/ci usage instructions (#7390) 1 year ago Release 0.34.0 (#8956) 2 months ago Modify CoC contact section 4 years ago Use correct command for running a particular spec (#9103) 1 month ago Update ISSUE_TEMPLATE to include forum (#7301) 1 year ago
LICENSE Fix LICENSE and add NOTICE file (#3903) 1 month ago
Makefile Use SOURCE_DATE_EPOCH only to determine compiler date (#9088) 1 week ago Fix LICENSE and add NOTICE file (#3903) 1 month ago Add link to GitHub repo to (#9163) 3 weeks ago
Vagrantfile Change from `bash` to `sh` (#5468) 2 years ago


Travis CI Build Status
CircleCI Build Status
Join the chat at
Code Triagers Badge


Crystal is a programming language with the following goals:

  • Have a syntax similar to Ruby (but compatibility with it is not a goal)
  • Statically type-checked but without having to specify the type of variables or method arguments.
  • Be able to call C code by writing bindings to it in Crystal.
  • Have compile-time evaluation and generation of code, to avoid boilerplate code.
  • Compile to efficient native code.


We love Ruby’s efficiency for writing code.

We love C’s efficiency for running code.

We want the best of both worlds.

We want the compiler to understand what we mean without having to specify types everywhere.

We want full OOP.

Oh, and we don’t want to write C code to make the code run faster.

Project Status

Crystal is still under heavy development. There can be breaking changes but we’re trying to keep them as minimum as possible.

The development is possible thanks to the community’s effort and the continued support of 84codes, Nikola Motor Company and every other sponsor.


Follow these instructions

Try it online



Questions or suggestions? Ask on the Crystal Forum, on our Gitter channel or IRC channel #crystal-lang at, or on Stack Overflow under the crystal-lang tag. There is also an archived Google Group.


The Crystal repository is hosted at crystal-lang/crystal on GitHub.

Read the general Contributing guide, and then:

  1. Fork it (
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request