have you ever noticed how you can start going in 1st by only using the clutch
of course this works with manuals only, but i think its cool that you can slip it like that

terrible for the clutch tho

 

That's because the car trys to compensate to keep the car at idle. That's also why you can get the car rolling, and take your foot off the gas, and it will drive real slowly by itself similar to an automatic rather than stall out. It will only stall if it just can't compensate enough. Like if you are going uphill. The car will stall.