it is free.....for 2 users only, that's all I need right now
Free 2-User Desktop Multiplier License - Userful
if you want more than 2......
"Want to have more than Two Users on your computer?
Userful supports up to 10 simultaneous users per computer. The software works with most standard video cards, so if you already have the hardware you can simply purchase the expansion licenses from us directly. If you need extra video cards or keyboards, we have a limited time special offer which enables you to get a 4-User starter kit (quad head video card plus four USB keyboards and mice) essentially for Free! This kit (on for a special price of $199) should enable you to upgrade your PC to support 4-Users. As a special limited-time bonus your first kit purchase will include a $200 coupon towards your first software purchase from Userful (Limited to new customers only and one per customer). That means the upgrade kit is actually FREE!"
I'm not trying to sell it, but I think it is a good idea probably for schools, libraries, or an internet cafe. Yeah, the extra monitors, keyboards, video cards, etc will cost a little money......but they also say it's better for the environment