SpaceTime[n 2] (also known as SpaceTime3D) was a 3D graphical user interface that displayed web pages in a 3d tabbed stack.

When using search engines such as Google, for example, SpaceTime loads the first ten results as a stack of pages.

On the day of the release, the San Jose Mercury News noted that the software was "the most advanced 3-D navigation system I've seen",[4] while TechCrunch commented that SpaceTime is "pure eye candy, sort of like Second Life meets Firefox.

"[8] Jack M. Germain, of TechNewsWorld described how "SpaceTime delivers on its promise to save me time and provide a revolutionary online searching too" stating that "while I continue to use the 3-D searching environment, though, I am having more fun than I should at work.

"[9] Edward N. Albro of PCWorld gave the beta browser a 2.5/5 stating that while its "visual results can make searches easier", that "for basic browsing, SpaceTime has no appeal" and that the browser was too "buggy and slow for basic browsing".