Moonchild Productions
Goanna logo


Goanna is the name for the Open Source layout and rendering engine as used in Unified XUL Platform (UXP) applications like the Pale Moon web browser and the Interlink mail/news client.

What does Goanna stand for?

As the name (a group of carnivorous lizards most common to East Asia and Australia) might suggest, it is a close relative to the Gecko engine which it has forked off of, which in turn has been rooted in the "next generation layout engine" that has been part of the Mozilla group of products for many years. As such, it shares many features with Gecko, although it is not a perfect match in how it behaves or what tags it supports and in what way. Similarly, it provides the base framework for the XUL language specification which will be maintained in Goanna.
Goanna aims to adhere to the existing HTML and CSS specifications closely, including following developments of the HTML5  specification where considered sane and desirable.

Version 4 of Goanna can be found in the Unified XUL Platform and Pale Moon 28, as well as any other applications that build on UXP, and will be updated as the platform is updated, independently of the products used in.

Why the different name?

Mostly to prevent confusion. Gecko is carried by the Mozilla Group as being synonymous with the version of their browser of the same version; from a technical perspective, this isn't correct to do and blurs the lines between framework/technology and an actual product building on it. Also, the name was changed to no longer be tied to something that is a registered trademark (Gecko is a trademark held by Oath (after acquisition of Netscape) and licensed for use exclusively to Mozilla) and our derivative code should not carry it anymore with its own, continued development by independent people unaffiliated with the current trademark owners.

For a while, Gecko was adopted as-is (as a name) with continued independent changes, to provide an indication of its general feature set and capabilities, using sub-version numbers as minor versions while carrying the major version 25, in line with the same (product) numbering scheme used by Mozilla for Gecko. However, it had become increasingly incorrect to do so: it was not a variant of Gecko v25. As it evolved, the need for its own name and versioning became more and more apparent, and so Goanna was created as a name for the forked-off layout engine in use.

In addition it created the false impression that the engine, and Pale Moon as a product, would be "an old (and outdated) version of Gecko" or "an old (and outdated) version of Firefox", respectively, neither of which are true.

Where can I find the source?

Goanna does not have a stand-alone source, since it can't be used as a stand-alone library. If you want to make use of the engine, you can build your application on the Unified XUL Platform (UXP).
The engine is an integral part of that platform, the source of which can be found on Gitea.

Legal information

Goanna and the Goanna logo are a trademark ™ of Moonchild Productions.
All rights reserved except where stated. The logo is Copyrighted.