Each quarter of dough will make approximately twelve ravioli. From here on out, the steps will differ based on whether you're using a ravioli maker or working by hand (if you have a stamp, follow the by-hand directions as well).
Other than that, not much difference. I'd still recommend using Source when you want to play. HALF-LIFE: Source is the same game as the original HALF-LIFE but it's graphics and physic engine is improved with the Source engine that is used in the HALF-LIFE 2. It is an improved version with better quality. If you want a Source experience choose it, but if you want to remember the old days, buy the original game.
Half-life is the time that it takes for 1/2 of the drug to be gone from the body. For example if 2 hours is the 1/2 life, in 2 hours there will be 1/2 of the drug left, in another 2 hours 1/4 left, in another 2 hours 1/8 left, in another 2 hours 1/16th left, etc.