Valgrind is a entire suite of open-source tools, including basic debugging, profiling, and more advanced techniques such as threading, memory management, and leak detection. For the purposes of this article, I will focus on Cachegrind, and in particular within the domain of Web applications. Although there are a number of developers contributing to Valgrind, Julian Seward is the original designer and author.

He talks about the cachegrind software and the PHP-based profiler that can create these files - XDebug. He also includes a list of a few of the cachegrind viewers including KCachegrind and Webgrind.

Cachegrind provides a nice graphical display of your profiling information but I run Mac OSX [...] What I needed was a way to replicate the old Xdebug 1.x functionality. From this the idea of "PHPGrind" was born. Right now its just a proof of concept but I am hoping with some more understanding of the cachegrind format I can make it into something as useful as the graphical versions.

His application grabs the cachegrind file and processes through it to pull out the events, version information and the target profiled and outputs them in a simple loop at end.

Commentors on the post also suggest Webgrind and MacallGrind.

Webgrind, the web frontend to Xdebug has been updated to version 0.7 with a few new features like: Support for directly loading a report through hash in url, Visual breakdowns of internal, class and procedural functions and calls to include/require and Version checking.

This new version (0.7) can be downloaded directly from its Google Code page.

For quite a while in the PHP Community (And even myself) I have heard people asking about either an online tool to work on cachegrind output files or a cross platform tool that would have the ability to do what KCacheGrind does on Linux but for Windows and OSX.

He mentions the origin of the idea for a cachegrind app as a part of the Google Summer of Code (that did get accepted and will be worked on by Chung-Yang Lee). The other, Webgrind is an independent project from the other but looks equally as promising.

Check out Vinu Thomas' thoughts on the matter too.

My about page has mentioned a web based frontend for Xdebug for some time. The project has a name now: The idea for Webgrind, a spin on Valgrind, came from lack of profiling tools for PHP, particularly on OSX. Though it is possible to install kcachegrind on osx it seems overkill for many uses and is definitely not as easy as unzipping a folder to the webroot.

He and Jacob Oettinger have started up the project and have posted some initial code over on the Google Code page for Webgrind. You can check out a screenshot of it in action here too.