Settings:
- xdebug.profiler_enable / xdebug.profiler_enable_trigger
Tools:
- KCacheGrind (Linux)
- WinCacheGrind (Windows)
- maccallgrind (Mac, non-free)
- webgrind (PHP script, multi-platform)
Browser extensions:
easy xdebug (firefox):
xdebug helper (chrome):
xdebug toggler for safari:
xdebug launcher for opera: