Opera Dragonfly
Well, it’s about time … Yesterday, Opera released an alpha version of Opera Dragonfly, their new developer tools.
I haven’t tested it much yet, but it looks promising. It is written in Javascript (those crazy Operans and their lust for web technologies ;)), and supposedly BSD licensed, although there’s no reference to the license in the source files.
The source is not available as a packaged download, you can just go to https://dragonfly.opera.com/app/, view the source and download the necessary components. To change where Opera downloads the developer tools, just go to opera:config, and change the Developer Tools URL. It’s just a web page with some special permissions, iirc.
This is only an alpha, but it’ll be interesting to see what comes out of it as it evolves.