Map Projection Systems were good ideas for ancient times, but not for the time being:
The Earth is a sphere, but a map is a 2D plane paper. To draw features on the earth on a plane paper, they need to be transformed in coordinate. For old times when there existed only papers as the media to show the earth on, the map and the projection system was a great idea.

But, what about now? Is it still the only way to do that?
Of course not.

With the computers today and graphical capabilities that they grant us, there is actually no need to see the world in a plane manner.

What is 3D Earth-View?
With this idea in mind, I implemented the "3D Earth View" environment in mGIS, in 2003, so that no projections was needed to display the map and the features on it. In this environment, you can turn the earth, zoom into it, like what you can do on a 2D map: pan it or zoom into it.

What I believed:
At that time I believed every existing GIS software should have had redesigned their environment to support a "3D Earth Viewing". Most of GIS softwares were able to display a 3D Terrain Model at that time. But, the fact was that it was just a portion of the whole Earth, not the whole Earth with more details on a portion of it!

Advantages:
- More realistic model to our picture from the earth and the features on it.
- Features looking much more similar to the corresponding ones on the earth than theirs on a projected map.
- One fixed model all around the globe.
- Able to carry on large-scale projects, plans, activities and tasks. (You usually can't do such projects/plans on a conventional 3D Terrain Model, because basically such models do not cover the curve of the earth.)

Disadvantages:
- Requires powerful software and hardware.
- Requires complicated mathematics/computations.