In this post from Padraic Brady, he compares some of the tools that are available to Ruby developers to some of their counterparts (if they exist) in PHP.

Anyways, here's the pitch. I've been using Ruby for a year now and my pet peeves with PHP started getting a bit too much to comfortably endure. [...] I don't like developing web applications with Ruby, or that thing Rails. Whatever it is. It's a framework, right? So I'm on a splurge of writing PHP tools for the same things in cahoots with folk like Travis Swicegood.

Tools he mentions include Autotest, Mutation testing, Mocha, Rspec, Heckle and some of their PHP counterparts like parts in PHPUnit and the DomDocument functionality.