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This is a list of independently maintained third-party open-source projects whose code is used by or included in WordPress 2.9 (which, as of September 2009, is in development).


  • imgAreaSelect. “A jQuery plugin for selecting a rectangular area of an image”
  • Jcrop. “The jQuery Image Cropping Plugin”
  • jQuery. “Α fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development”
  • kses. “HTML/XHTML filter that only allows some elements and attributes”
  • MagpieRSS. “A simple RSS integration tool” / “MagpieRSS provides an XML-based (expat) RSS parser in PHP”
  • PclZip. “Compression and extraction functions for ZIP archives”
  • PemFTP. “An FTP implementation in pure PHP”
  • PHPMailer. “Α PHP email transport class”
  • Portable PHP password hashing framework. “A portable public-domain password-hashing framework for use in PHP applications”
  • Services_JSON. “A simple encoder and decoder for JSON notation”
  • SimplePie. “Α very fast and easy-to-use class, written in PHP, that puts the ‘simple’ back into ‘really simple syndication’”
  • Snoopy. “The web client class for PHP”
  • SWFUpload. “A small JavaScript/Flash [upload] library to get the best of both worlds”
  • The Incutio XML-RPC Library for PHP.
  • Thickbox. “One Box To Rule Them All”
  • TinyMCE. “A platform-independent web-based Javascript HTML WYSIWYG editor control”


  • Cropper. “JavaScript Image Cropper UI, using Prototype & script.aculo.us”
  • Prototype. “A JavaScript Framework that aims to ease development of dynamic web applications”
  • script.aculo.us. “Easy-to-use, cross-browser user interface JavaScript libraries”