What program should be used to run games on the PC

First of all,give us more info,tell us exactly what do you mean?

Do you need a program that boosts PC performace?

Do you need a program like Steam,in which you can purchase games online?

Do you need an OS(Operating System) like Windows or Mac OS X?

Do you want to run console games(PS3,X-BOX) on PC?

Do you need a program to let games run without CD/DVD/BD?


For online gaming, Flash is most popular. Shockwave is second (but older), and Java is dead :P