Download MAVLink here: https://github.com/mavlink/mavlink/downloads

For Windows a Nullsoft installer is provided. It will walk you through the installation of the library onto your system.

For linux, the library is provided both in a debian package (useful for debian and ubuntu) and a self extracting tarball version (compatible with all mac/ linux versions).

For all linux/ mac versions the self extracting acrhive can be used as follows:

sudo gdeb-gtk ./mavlink-1.0.0-Linux.deb

You should be able to double-click the debian package, or you can manually start gdebi-gtk package installer with the command:

sudo gdeb-gtk ./mavlink-1.0.0-Linux.deb