Opera Dragonfly

It supports debugging JavaScript, viewing the DOM, monitoring network traffic, previewing resources, editing colors, etc.

Opera Dragonfly automatically updates to the latest version available, when connected to the Internet.

[1] On 21 September 2011, the Opera Dragonfly team announced that from then on releases would be more focused on improvements to individual components, e.g. the DOM inspector or the UI framework.

As soon as a feature for a certain component was implemented, it would be put on the experimental path for some initial testing.

As part of the new release strategy, they switched over Opera Dragonfly to a new version scheme: .....