I am always on the lookout for good IDEs, including the ones for PHP. There are several decent ones on the market. From the open-source ones, Eclipse with PDT does a decent job, for local development, if you do not mind extra weight of a JDK-based IDE. It has some other issues as well (poor support of on-the-server development via SFTP and forcing the use of pre-configured projects are a few), but Eclipse is not what we'd like to discuss in this post, today.
Today I stumbled upon a new (for me) Windows-based, PHP IDE: EngInSite PHP IDE and I was, quite frankly, blown away! EngInSite is, quite simply, the best PHP IDE on a Windows platform. I have been playing around with it for a couple hours now and I have to yet find a feature I would like that it does not have. It's a very rare example of a perfect tool.
Few important features from the long list of this IDE's capabilities: