Pixar was founded as the Graphics Group, one third of the Computer Division of Lucasfilm that was launched in 1979. At NYIT, the researchers worked on an experimental film called The Works; it was never released for public viewing.
Eventually, the team began working on film sequences, produced by Lucasfilm, or worked collectively with Industrial Light and Magic on special effects. The group was purchased in 1986 by Steve Jobs shortly after he left Apple Computer. He paid $5 million to George Lucas and put $5 million as capital into the company.
Early successes included campaigns for Tropicana, Listerine, and LifeSavers. During this period, Pixar continued its relationship with Walt Disney Feature Animation, a studio whose corporate parent would ultimately become its most important partner.

Source: Wikipedia

Pixar uses the Lamp as its mascot. Another interesting fact about Pixar movies is most Pixar movies have short animated movies as a prologue. Here is a funny example:

There is also a great spoof video featuring the Pixar Lamp. Enjoy!