Williams Innovations is a company that creates alternate energy sources and other innovative inventions. The CEO was Simon Williams aka Wonder Man.
Everything is Wonderful
Desperate to save his company, Simon tries to plead Tony not to do this, but the latter didn't respond because he wasn't paying attention which angers Simon and left Stark Tower.
In his desire to make Stark suffer on what he did to his company, he went to his brother, the Grim Reaper who escorted him to the hidden A.I.M. base where he was transformed into Wonder Man by M.O.D.O.C. and then flew off to Stark Tower.
He then began to make Tony suffer for "destroying" his company. Tony tries to explain, but he didn't listen causing a brutal and destructive battle between the two.
When Wonder Man was disintegrated by his ionic instability, Tony revealed to the Avengers that he bought Simon's company to save it, because it wasn't going to last forever, he wanted to say what he built and work with him.
After Simon's demise, it was presumed that Williams Innovations was shut down after he refuses to listen to Tony's true reasons of buying his company.