A lightweight, cross-browser JavaScript message logging utility
Blackbird was inspired by an article written by David F Miller on JavaScript logging. I wanted to make a universal JavaScript logging console that I could use in modern and older browsers (e.g. IE6 ). I also wanted something that was attractive, lightweight and easy to integrate into existing code bases.

This was released as an open-source project in 2008 and is used by thousands of developers.
Product site, including demos, documentation and usage notes