Complex sentence: AdForce (formerly ADFC on NASDAQ), founded by the Steelbergs in 1994 and grown into the world's largest centralized independent ad serving and management solution, was acquired by CMGI after going public for more than $500 million in 1999.
Split into simpler sentences: AdForce (formerly ADFC on NASDAQ), became the world's largest centralized independent ad serving and management solution. It was acquired by CMGI after going public for more than $500 million in 1999.