What does ROFL stand for?

What does ROFL mean?

ROFL	Rolling On the Floor Laughing Miscellaneous » Funnies
ROFL	Rolls On Floor, Laughing Internet » Chat
ROFL	Rolling On the Floor, Laughing Computing » Texting
ROFL	Really Old Farts Linger Academic & Science » Amateur Radio
ROFL	Reaching Out For Love Community » Religion
ROFL	Repeat Only Four Lines Community » Performing Arts
ROFL	Real Orrible Funny Laugh Miscellaneous » Funnies
ROFL	Rolf One Forever Lives Miscellaneous » Unclassified
ROFL	Rogues Of Forbidden Legion Miscellaneous » Unclassified
ROFL	Right Of Free Landing Governmental » Transportation
ROFL	Rolling On The Floor Medical » Human Genome