Derick Rethans has posted about some new browser extensions for the popular PHP-based debugger Xdebug. These are to replace the helper that is no longer available on FireFox's site (download).

Years ago I wrote about a Firefox extension that allows you to start an Xdebug debugging session by clicking on an icon in Firefox' status bar. For some unexplained reason, this extension is no longer available through Firefox' addon-site. [...] There are now a few other browser extensions that do the same thing.

He lists three new extensions that can most of what you'd need to keep your testing going - easy Xdebug, Xdebug enabler (for Chrome) and this blog post with a pure Javascript method done with bookmarklets.