KCachegrind visualizes traces generated by profiling, including a tree map and a call graph visualization of the calls happening. It's designed to be fast for very large programs like KDE applications.
Klsof is a frontend to the command line utility lsof.
TRAM (short for Trace Analyse Modules) is a collection of plug-ins for the sofware Tulip (see www.tulip-software.org), which is extended in this way to analyse and display traces (resp. trace-data).