Vala is available on a large variety of Linux distributions. Mostly you want to install other development files for libraries, that you want to use with vala.
You should avoid long-term-support realeases, because they often have only very old versions of vala.
Development files usually come in
*-devel packages, for example
sudo dnf install vala
You need to install
*-dev packages, to get development files on Debian.
sudo apt install valac
sudo pacman -S vala
First you install the port:
cd /usr/ports/lang/vala/ && make install clean
And then you can add the package:
pkg install vala
MSYS2 provides a Linux-like environment for Windows. First install MSYS2, then vala:
pacman -S mingw-w64-x86_64-gcc pacman -S mingw-w64-x86_64-pkg-config pacman -S mingw-w64-x86_64-vala
You also need to install all libraries you want to use individually.
Windows Subsystem for Windows (WSL)#
Install a Linux distribution in WSL and then go on with the installation instructions for Linux.
Mac OS X#
To install Vala on you can use brew, a package manager for OS X:
brew install vala