On Debian and Ubuntu

In Debian derived distributions, you can use the official Crystal repository.

Setup repository

First you have to add the repository to your APT configuration. For easy setup just run in your command line:

curl -sSL https://dist.crystal-lang.org/apt/setup.sh | sudo bash

That will add the signing key and the repository configuration. If you prefer to do it manually, execute the following commands:

curl -sL "https://keybase.io/crystal/pgp_keys.asc" | sudo apt-key add -
echo "deb https://dist.crystal-lang.org/apt crystal main" | sudo tee /etc/apt/sources.list.d/crystal.list
sudo apt-get update

Install

Once the repository is configured you're ready to install Crystal:

sudo apt install crystal

The following packages are not required, but recommended for using the respective features in the standard library:

sudo apt install libssl-dev      # for using OpenSSL
sudo apt install libxml2-dev     # for using XML
sudo apt install libyaml-dev     # for using YAML
sudo apt install libgmp-dev      # for using Big numbers
sudo apt install libreadline-dev # for using Readline

For building the Crystal compiler itself, a few other dependencies are needed, see wiki page. They are not required for regular compiler use.

Upgrade

When a new Crystal version is released you can upgrade your system using:

sudo apt update
sudo apt install crystal