PHP

A framework that takes in the XML file generated by Google Calendar and makes it PHP friendly. There are hooks that allow developers to loop through and generate their own themes outputting the necessary HTML.

PHP implementation for the BitPay cryptographically secure RESTful API.

A simple PHP script that will automagically create a JS/CSS/DHTML powered image gallery when dropped into a directory containing images.

A PHP CMS that uses MySQL, SQLite or PostgreSQL with a simple drag-n-drop page hierarchy. Easily extended with plugins and themes.

Subrion is a PHP/MySQL based CMS and framework that allows you to build websites for any purpose. From blog to corporate mega portal. Many free templates and premium scripts available.

Create dynamic XSPF playlists based on ID3 tags in MP3 files. The zip package contains everything you need to get started. Move this folder out to your website root, and upload your MP3s.

A petite library of essential encryption functions for PHP 5.3 - 7.1. Block ciphers, stream ciphers, Rivest's ciphers, key derivation, time-safe string comparison and secure random byte generation.

A standards compliant HTML filter library written in PHP. HTML Purifier will not only remove all malicious code (XSS) with a thoroughly audited, secure yet permissive whitelist, but it will also make sure your documents are standards compliant.

A popular general purpose HTML-embedded scripting language that is especially suited for Web development. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP specific features.

Opulence is a PHP web application framework that simplifies the creating and maintaining of a secure, scaleable web site. Things like database management, caching, ORM, page templates and routing are a cinch.