Source: http://www.labnol.org/software/browsers/sleipnir-browser-portable-internet-explorer/3954/
The browser is extremely fast and supports the rendering engine of both IE & Firefox so you can change engines on the fly if you encounter a website that supports only one particular engine.
Here are some screenshots of Sleipnir:
Almost every feature in Sleipnir is customizable and the browser is therefore especially popular among geeks and advanced users who can fine-tune it according to their needs.
When you select some text on a web page, there’s a nice magnification lens that appears after a brief interval allowing you to do more things with that text selection.
IDG says that Sleipnir has a 9% share in the web browser market of Japan. I’ll probably not dump IE, Firefox or Opera for Sleipnir browser but it’s definitely a good attempt and worth keeping a watch.
And for mobile profession who like to carry their computer on a USB Drive, the portable edition of Sleipnir (download page) may just do the trick - it runs on the IE engine by default though you also have the option to use the Firefox Gecko engine.
Use Sleipnir Web Browser as Portable Internet Explorer - Digital Inspiration by Amit Agarwal