As IT environments become more complex, so does application performance management. IT professionals need tools that are up for the new challenge. "Applications are becoming increasingly difficult to troubleshoot, and [it's becoming more difficult to] understand how users are interacting with them," said Jonah Kowall, research vice president of IT operations management at Stamford, Conn.-based Gartner Inc. "Because applications are so diverse, there are a lot of different approaches and solution...