Vim is an advanced text editor that provide the power of Unix editor ‘Vi’, with a more complete feature set.

Vim is a highly configurable text editor built to enable efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems.

Vim is often called a “programmer’s editor,” and so useful for programming that many consider it an entire IDE. It’s not just for programmers, Vim is perfect for all kinds of text editing, from composing email to editing configuration files.

Features
- highly configurable.
- syntax highlightning.
- windows split (both vertically as well as horrizontally).
- tabbing.
- folding.
- unicode support.
- flexible indenting.
- …

The Good
Vim is a professional text editor targeting mainly programmers, but it can be also used by any other type of user.
It received the best text editor award from readers of the Linux Journal magazine in 2001, 2002, 2003 , 2004 and 2005, which I think tells a lot about its efficiency.

The Bad
The bad and ugly part about Vim would be for most users the fact that they must do the learning first in order to be able to use it.

The Truth
Vim is a multi-platform text editor, Vim provides all the functionality of a regular text editor, such as spell checking, Unicode support, possibility of undo/redo the most recent actions, integrated help but it has also some features of its own which make it a powerful and reliable tool.

So far so good, To get a better idea on what Vim is, you can also check www.vim.org :)