MFSL, now known as MoFi, is a mastering house/record company dedicated to releasing audiophile grade releases. Using original master tapes they produce high quality vinyl and 24k gold CD's containing the highest quality audio for the format. They are extremely hard to find and expensive. They are highly prized by audiophiles the world over.
"Dude, I listened to the MFSL version of Dark Side of the Moon and I completely forgot where I was for a while"