Vim

Vim is my favorite text editor. It's an OpenSource editor that's powerful, fast, and full of features. I've tried other editors, EMACS, GEdit, Nedit, etc., and all of them are very high quality editors and have their merits. Time and time again I return to Vim because it works the way I do. GVim is the graphical version of this wonderful editor.


From the Vim website-

"What is Vim?"
An explanation in six kilobytes.

Vim ("Vi IMproved") is a "vi clone", ie
a program similar to the text editor "vi".

Vim works in textmode in every terminal,
but it also has a graphic user interface,
ie menus and support for the mouse.

Availability:
Vim is available for many platforms and has many added features
compared to Vi. (see http://www.vim.org/viusers.php)
Vim is compatible to almost all Vi commands - except Vi's bugs. ;-)

Operating Systems:
Vim is available for many systems: AmigaOS, Atari MiNT, BeOS, DOS,
MacOS, NextStep, OS/2, OSF, RiscOS, SGI, UNIX, VMS, Win16 + Win32
(Windows95/98/00/NT) - and especially FreeBSD and Linux. :-)

Copyright:
The copyright is in the hands of the main author
and maintainer, Bram Moolenaar .
Vim is "charity-ware", ie you are encouraged to make
a donation to orphans in Uganda (see ":help uganda").

Source:
Vim is OpenSource and everybody is welcome to help improve it!