Gecko-Based Internet Browser with Addon Support Downloads
Gecko is an open source layout engine that is used by popular apps like the Firefox browser or the Thunderbird email client, and in many other open source software projects.
An extension is a piece of software, also known as plugin or addon, that was specifically designed to extend or enhance the features and functionality of a specific application.
This collection contains several web browsing applications that are based on the Gecko layout engine. Furthermore, all these web browsers will allow you to install various extensions in order to add new feature or enhance older ones.