The new version of the open source web development tool, Firebug 2.0, has has a major facelift and is powered by a new debugging engine.
Announcing the release of the new version, Firebug's lead developer, Jan “Honza” Odvarko, wrote:
Firebug 2 introduces many new features and bug fixes also because we completely removed dependency on the ancient Firefox debugging engine (a.k.a. JSD1) and incorporated a new debugging engine known as JSD2.
Its release coincides with Firefox 30, which is a minor mainly bug fixing release, but it anticipates a major change in Firefox 31 which sees the removal of JSD1 from Firefox.
Syntax colouring is included for HTML and CSS.
Other improvements are that:
The EventBug extension for Dom Events has been integrated into the add-on.
The HTML panel search has been improved and now supports regular expressions and CSS selectors.
Code auto complete has been improved. It is available in the Command Editor within the console panel, also works in the breakpoint-condition popup dialog where it offers variables in the current scope and when editing HTML and SVG attributes
A new option in the Console panel groups logs from the same location
You can now show or hide specific Firebug 2.0 panels
A new Color As Authored option in the CSS panel for comparing style information with the output of the browser
Ability to create new HTML attributes faster
Ability to inspect registered mutation observers for any given element.
This video provides a walkthrough of many of the new features:
Once you install Firebug, it takes over the default Firefox Developer Tools shortcut (F12).