Resources and links on debugging, tracing and profiling Drupal

This is a collection of useful links on debugging, tracing, and profiling Drupal.

• Drupal devel module has some support for xdebug. It is valuable for other info as well such as page load times, list of queries run for the page, ...etc.
• The Form Inspect module is a devel add on that dumps the form ID and the array of form values.
• Drupal's trace module provides tracing for hooks, database queries and errors. Read the author's article on it.
• Simple debugging tips for Drupal that does not involve an IDE nor a real debugger but worth reading and using.
• Article on Debugging Drupal with ActiveState Komodo, on drupal.org.uk. This is a well written article covering local debugging. Remote debugging is a bit more tricky to get going, and setting it up with multiuser debugging is more challenging.
• Article on setting Komodo for PHP on Mac OSX. Although the article says this is remote debugging, everything is running on the same box, and no need to map local files to remote ones.
• Debugging Drupal 6.x with Eclipse and Xdebug.
• Another Eclipse and Xdebug article.
• Debugging PHP on php.net.
• An somewhat old forum post on drupal.org on debugging PHP.
• An article by Steve M of OpenConcept on Debugging PHP on Ubuntu Feisty Fawn.
• Adam Harvey is being mentored by Derick Rethans during the Google Summer of Code 2007 to develop a platform independent Xdebug client for PHP.

Got a good article about debugging Drupal or hints and tips on that? Post it as a comment below.