Kcachegrind - Callgrind is a profiling tool and KCachegrind is able to visualize output of the profilers.
Webgrind - Webgrind is an Xdebug profiling web frontend in PHP5.
PyCharm - Python & Django IDE with intelligent code completion, on-the-fly error checking, quick-fixes, and much more...
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.
perf - Perf is a simple app monitoring solution paired with meaningful alerts.
Oink - Oink is a Rails plugin and log parser to help narrow down the source(s) of increased memory usage in rails applications.