What to use to make a VPS server

Anyone have any idea what to use to run a VPS server? You know how hosts that run VPS servers have a software kinda like VM I guess But I doubt its VM Ware there using anyone have any idea?
Answer #1
I don’t exactly now what you mean, but I think this will help you, it’s called XAMPP:
http://www.apachefriends.org/en/xampp.html
Answer #2
Na Im not talking about a website Im talking about what software does a web host use to make everyone a Virtual server with.
Okay you know like a VPS is basicly a server that hosts like 5 or more sites each user has access to only there server on that server.
I think its like VM Ware that they use but VM Ware runns kinda slow on my PC even thou I have 3 GB of ram.
I wanna know what I should use to run my own VPS server like is I wanted people to be able to login thru RDC and all I wanna know what software there using.
Hard for me to explain but if you have ever used a VPS server you will know what im talking about they have to be using something that splits there users from other users within 1 server.