[Dimensio]

It's based on the same codebase as Netscape, so it's going to look the same. Basically it is the functionality of Netscape in an open-source package with all of the commercial bloat removed.

[Tree of Liberty]

It's based on the same codebase as Netscape, so it's going to look the same

Actually, it's the other way around. Mozilla was started as an open-source project by Netscape to totally re-write the code from the ground up. After a few years of development by Mozilla, Netscape abandoned their old code base and adopted the Mozilla code starting with Netscape 6.0. The GUI itself is skinable, and it happens that they include a "classic" skin that looks like previous versions of Netscape, probably to fascilitate migration.