Officially we support Ubuntu, Debian, CentOS and Fedora on your servers. Generally though because our client is open source and runs as a very standard package, it should be compatible with almost all modern unix based systems.
You can view the full source code for the ServerAuth agent here: (https://github.com/serverauth-com/serverauth-agent)
Absolutely, however with a few caveats.
As mentioned above, we currently officially support CentOS, Fedora, Ubuntu and Debian. But the ServerAuth agent is open source and is built using Golang, so can be compiled and run on your server.
For details and assistance in doing so, please get in touch, letting us know your operating system and we'll do our best to help get you up and running.