PUBLIC MARKS from camel with tag firebug

Companion.JS (pronounced Companion dot JS or CJS) is a Javascript debugger for IE. The current version is 0.2, adding the following features to IE : * Detailled javascript error reporting (call stack and real file name where the error occured). * "Firebug"-like Console API feature. * Javascript console feature useful to inspect javascript objects at runtime. * A toolbar icon to open the Companion.JS panel.

FirePHP - Capabilities Definition < Specifications < Reference

Debugging PHP With Firebug