Eclipse - PDT - Download
The PDT project provides a PHP Development Tools framework for the Eclipse platform. This project encompasses all development components necessary to develop PHP and facilitate extensibility. It leverages the existing Web Tools Platform (WTP) and Dynamic Languages Toolkit (DLTK) in providing developers with PHP capabilities.
Netbeans - Download
The NetBeans project offers a version of the IDE tailor-made for developing PHP sites. PHP developers do not need to install the full Java Development Kit (JDK) to run the NetBeans PHP IDE, the standard Java Runtime Environment (JRE) is sufficient.
Aptana - Download
Aptana Studio is a complete web development environment that combines powerful authoring tools for HTML, CSS, and JavaScript, along with thousands of additional plugins created by the community.
Quanta Plus - Download
Quanta Plus is a highly stable and feature rich web development environment. The vision with Quanta has always been to start with the best architectural foundations, design for efficient and natural use and enable maximal user extensibility.
jEdit - Download
jEdit is a mature programmer's text editor with hundreds (counting the time developing plugins) of person-years of development behind it.