Crystal doesn't support Windows yet, but if you're using Windows 10 you can (experimentally) try Crystal using Bash on Ubuntu on Windows, an experimental Bash environment running on Windows. The installation instructions are the same as for Debian/Ubuntu, but there are a few rough edges to be aware of.
Don't forget - this is highly experimental.
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:
sudo apt-key adv --keyserver keys.gnupg.net --recv-keys 09617FD37CC06B54
echo "deb https://dist.crystal-lang.org/apt crystal main" | sudo tee /etc/apt/sources.list.d/crystal.list
sudo apt-get update
Crystal needs a C compiler (cc) and linker (ld) to be able to compile Crystal programs - so you should install them:
sudo apt-get install clang binutils
Once the repository is configured and you have the dependencies, you're ready to install Crystal:
sudo apt-get install crystal
When a new Crystal version is released you can upgrade your system using:
sudo apt-get update
sudo apt-get install crystal