Sleipnir - Horrible Name for a browser, but cool formatting options

Sleipnir released version 2.7.2 in hopes of gaining a larger market share in the internet browser application market. You still have your tabbed browsing, and lots of customization. Download location

Sleipnir Overview
Sleipnir is designed to be a highly customizable browser that you can configure to suit your individual needs. With Sleipnir, you can create your ideal browser by changing the design, skin, and visual appearance. You can also add custom functionality to Sleipnir with a wide range of plugins and user scripts. Users love Seipnir for it's unique blend of high-performance and customizability.

Sleipnir lets you choose.
Do you have IE and Firefox installed? Sleinir allows you to quickly switch between Trident and Gecko based formatting engines. Trident is IE and Gecko is Firefox. So basically, if you like the way a site looks using one over the other, it's now simple to switch to it, using one browser application.