Meson is implemented in Python 3, and requires 3.5 or newer. If your operating system provides a package manager, you should install it with that. On Debian, for example, you can simply:
$ sudo apt install meson
For platforms that don't have a package manager, you need to download it from Python's home page. See the following link for more information.
In order to build the oz2 software you need the following libraries: sdl2, sdl2_image, sdl2_gfx and sdl2_ttf. On Debian you can install these libraries as:
$ sudo apt install libsdl2-dev libsdl2-image-dev libsdl2-ttf-dev libsdl2-gfx-dev
The Meson build system is generally considered stable and ready for production.
The meson program is used to configure the source directory and generates a ninja build file. Meson only supports out-of-tree builds, and must be passed a directory to put built and generated sources into. We'll call that directory "build" for examples.
$ meson build/
To see a description of your options you can run meson configure along with a build directory to view the selected options for. This will show your meson global arguments and project arguments, along with their defaults and your local settings.
$ meson configure build/
Once you've run the initial meson command successfully you can use your configured backend to build the project. With ninja, the -C option can be be used to point at a directory to build.
$ ninja -C build/
The default install target (executed via, e.g., ninja install) does installing with reasonable default options. Sometimes you need to install to a different directory than the install prefix. This is most common when building rpm or deb packages. This is done with the DESTDIR environment variable and it is used just like with other build systems:
$ DESTDIR=/path/to/staging/area ninja -C build/ install