Upload & Sell: On
There are almost as many QR systems as there are tripod brands. I started with Manfrotto tripods and monopods, which generally come with their RC2, RC4, or "universal slider" QR systems. After a few years, I switched to Arca-Swiss (A-S) compatible systems, made by RRS, Kirk, A-S, Hejnar, and many other companies. In general, the A-S clamps and plates are interchangeable. I find the A-S camera L-brackets from RRS to be especially useful, and that's what prompted me to switch to A-S.
Here's a few links that might be useful...
... and here's a few photos of my A-S clamps and etc. The first shows my Manfrotto 468MG head with an RRS QR clamp on it. More recently, I converted the 468MG to A-S using a dedicated Wimberley clamp that attaches directly to the post coming off the ball head. The second photo shows my 410 geared head with a RRS QR clamp on it (still use this). The last two show my 5D with an RRS L-bracket.