Simple error handler class can be use to intercept and log PHP execution errors. The class provides an error handler function that outputs a stack back-trace with the functions, arguments, file, and lines of where an error occurs, as well the values of super-global variables $_GET, $_POST, and $_FILES, and also the IP address of the current user accessing the site. When used with a MySQL class that triggers PHP errors on a MySQL error, you can use it as a means to debug broken MySQL queries.
DM Performance Meter is intended for measuring the execution time of a script (or its parts). It measures the time taken to execute the part of a PHP script between specified start and end points. It also can measure the time of arbitrary checkpoints. It supports: setting multiple named check points; output measurement results as plain text, HTML comments, and HTML unordered lists; and logging results to CSV files.
IAM OPML Parser Class parses an OPML file (provided its URL) and returns an array. This array contains, for each of the OPML file's elements, the following attributes: link_url, link_name, link_target, link_description, link_rss, created (date of creation), and type (link type: RSS, HTML, etc.). The class uses file_get_contents() to retrieve the contents of the OPML file, and then the XML extension is used to parse and store the file’s data in an associative array, where each outline element is stored using a different array index.
PHP Command Class is a PHP class that is allows one to create a single index page that is controlled using a command and sub-command pair. The command and sub-command are stored in a database for quick lookup, and they can be used for creating menus. This class is designed to use MySQL, but any database that has an API for PHP can be used by using the correct database class to handle the queries. Full documentation and comments can be found in the code.