[Sites] Everything

Alright, I was searching on here the other day and saw a few posts about a few different things. Now, the thing is, I was not sure what was what. I know yaXay, and thats it. What are all the abbreviations for the popular designing, freelancing sites out there? and what are there links!? I thought this topic would be great for new members if they needed it, so post links and abbreviations of all the different free lancing sites. Thanks much and post away!