Microsoft's announcement that it would like to buy search engine Yahoo for $44.6bn (£22.4bn) is major news for the computer sector.
Here we take a closer look at the two US giants.
MICROSOFT
The world's dominant provider of personal computer operating systems, Microsoft has a market share of about 90%.
Founded in 1975, it now enjoys annual revenues of $51bn and has a workforce of 79,000.
Headquartered in Washington State, founder Bill Gates is the world's richest man.
Mr Gates has an estimated personal fortune of $56bn.
The company's dominant market position has led to numerous criticisms that it stifles competition.
Earlier this month the European Commission launched two new anti-competition investigations into the company.
The Commission previously fined Microsoft a record 497m euros for anti-competition practices in 2004, a ruling Microsoft eventually lost on appeal last year.
YAHOO
Yahoo is the world's second most popular internet search engine, yet it trails
far behind market leader Google.
A study in August last year showed that Google carried out 37 billion searches that month, while Yahoo did only 8.5 billion.
As a result, Yahoo's advertising revenues are also far lower than Google's.
Yahoo posted a loss for all four quarters of 2007, and is now continuing with job cuts and other cost reduction work.
Founded in 1995, Yahoo is based in Sunnyvale, California, and led by chief executive Jerry Yang.
It currently employs 14,300 staff.
Here we take a closer look at the two US giants.
MICROSOFT
The world's dominant provider of personal computer operating systems, Microsoft has a market share of about 90%.
Founded in 1975, it now enjoys annual revenues of $51bn and has a workforce of 79,000.
Headquartered in Washington State, founder Bill Gates is the world's richest man.
Mr Gates has an estimated personal fortune of $56bn.
The company's dominant market position has led to numerous criticisms that it stifles competition.
Earlier this month the European Commission launched two new anti-competition investigations into the company.
The Commission previously fined Microsoft a record 497m euros for anti-competition practices in 2004, a ruling Microsoft eventually lost on appeal last year.
YAHOO
Yahoo is the world's second most popular internet search engine, yet it trails
far behind market leader Google.A study in August last year showed that Google carried out 37 billion searches that month, while Yahoo did only 8.5 billion.
As a result, Yahoo's advertising revenues are also far lower than Google's.
Yahoo posted a loss for all four quarters of 2007, and is now continuing with job cuts and other cost reduction work.
Founded in 1995, Yahoo is based in Sunnyvale, California, and led by chief executive Jerry Yang.
It currently employs 14,300 staff.