Apple Becomes Most Valuable Company of All Time
reuters.com
reuters.com
Microsoft in 1999 was worth $620Bn, which in 2012 dollars would be around $853Bn.
http://www.computerworld.com/s/article/9230400/Apple_not_mos...
If you strip out assets and talk about what the most valuable "company operation" is it's certainly Apple by a long margin.