Hewlett Packard is a computer company. They were formed in 1939 (before even Greig was formed) as a electronic equipment manufacturer and have grown to be one of the largest IT suppliers in the world.
HP bought Compaq in 2001/2002, effectively cutting the number of large PC manufacturers in the world to three.
Over the last 20 years, HP's main profit engine has been their printers. They made the laser printer popular and derive a large part of their revenue from consumables. HP are also quite famous for their calculators.
HP are great supporters of Linux, notable for their support of the non-commercial Debian distribution. The CTO of Linux at HP, Bdale Garbee, has served a term as the Debian project leader.
They are also one of the WlugSponsors, generously providing a blade chassis with five blade servers.
