As part of an ongoing project I'm trying to decide how I can rewrite a .NET application to work on any type of client (Currently Windows, android tablet, and iphone/pad)

Easiest way would seem to be some kind of webpage, however the obvious things like VBScript etc are running a) client side, b) Windows only.

Can anyone think of a decent way to do a server-side (as it needs to access the computers ports so can't be client side run), that would run over at least those 3 OS? (or even 2 if possible :P Preferably with builtin comm support, but could be addins etc if free)

Many thanks,