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Ary Borenszweig 76bc62962b
Fix flake: compress handler specs (#7819)
1 day ago
.circleci Update CI to use 0.28.0 1 month ago
bin Move VERSION inside ./src (#7804) 4 days ago
etc Add --warnings --error-on-warnings --exclude-warnings compiler options 1 month ago
man Docs: Update man page with new options (#5554) (#6259) 11 months ago
samples Samples: sync thread rounds 1 month ago
scripts Unicode: update to version 12.0.0 (#7721) 1 month ago
spec Fix flake: compress handler specs (#7819) 1 day ago
src Compiler: don't virtualize types in Union(...) (#7815) 2 days ago
.dockerignore Dockerfile now uses `make`. Fixes build after addition of LLVM extensions in c++. 3 years ago
.editorconfig Mark .editorconfig as root (#6031) 1 year ago
.gitignore Fix docs path in .gitignore and Makefile (#5217) 1 year ago
.travis.yml Run formatter in travis. Update /bin/ci usage instructions (#7390) 3 months ago Fix in 3 years ago Release 0.28.0 (#7663) 1 month ago Modify CoC contact section 3 years ago Mention git pre-commit hook in (#7617) 1 month ago Update ISSUE_TEMPLATE to include forum (#7301) 4 months ago
LICENSE Update LICENSE's copyright year (#7246) 4 months ago
Makefile Keep embedded libraries in the compiled compiler 1 month ago Reorganize community section in README, add forum (#7235) 4 months ago
Vagrantfile Change from `bash` to `sh` (#5468) 1 year ago


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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, 84codes’ support, and every BountySource supporter.


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.


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