Over the past nine years of having fun with PHP, began to see that there are five categories of tools that I rely on more than any others. Sure, I've got a code beautifier, a standards checker, and a hand full of hand-written scripts I use for various things to make life easier. However when it comes down to it, there are five that I rely on every day. So here they are in acceding order of importance. Let me know, what are your five? (let's not start a meme or anything though, ok?)

His list of five is: a unit testing tool, a debugger, an ERD tool (Entity Relationship Diagram), a version control system and, finally, a framework (pick a framework, any framework).