here is the story. my 3 years old nephew (which i love him so much) is so curious about computers. every time he comes to visit (which is not rarely), he insist on helping me with my computer works. of course he thinks he is helping but i can't have him messing my projects. so i wondered if i can (peacefully) share the computer with him. i searched and i found out about Multiseat.
A multiseat, multi-station or multiterminal configuration is a single computer which supports multiple independent local users at the same time. In modern usage the terms refer to multiple users using one personal computer, each with their own console, consisting of a keyboard a mouse, a monitor, and possibly headphones --Wikipedia
so obviously that was the solution. time to get my hands dirty on the code :)
as it may be obvious, there are numbers of solution to do configure the GNU/Linux system to fit my need. so, in the following next articles (below links), i will explain these solution as i experienced them. i try to do them separately and independently, so you can skip ones you are not interested about. here are what i found: