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.

Within a major version, language features won't be removed or changed in any way that could prevent a Crystal program written with that version from compiling and working. The built-in standard library might be enriched, but it will always be done with backwards compatibility in mind.

Development of the Crystal language is possible thanks to the community's effort and the continued support of 84codes, Nikola Motor Company and every other sponsor.

Follow these installation instructions

play.crystal-lang.org

• Language Reference
• Standard library API
• Roadmap

Have any questions or suggestions? Ask on the Crystal Forum, on our Gitter channel or IRC channel #crystal-lang at irc.libera.chat, 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 (https://github.com/crystal-lang/crystal/fork)
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