Will Server Edition use multiple operating systems?

We’re thinking of purchasing the server edition of Manager but would install it on a computer running Ubuntu and would need to access it from a laptop running Windows 7. Would these different operating systems create a problem?
Also, can we put two businesses on the server edition or would we have to purchase it twice?

One instance / purchase of Manager Server edition running on either Ubuntu, Windows, Mac can host multiple companies / businesses and can be accessed from any standard browser capable device running on any operating system based anywhere (local and remote) provided the networking side of things have been taken care of.

Server Edition | Manager Online accounting with unlimited businesses, unlimited users and without monthly fees.

Thank you. I have now learned what a “network” is (I thought I knew!). So will be purchasing the server edition soon.