Gedit

gedit is a text editor for the GNOME desktop environment, Mac OS X and Microsoft Windows. Designed as a general purpose text editor, gedit emphasizes simplicity and ease of use. It includes tools for editing source code and structured text such as markup languages.

It is designed to have a clean, simple graphical user interface according to the philosophy of the GNOME project, and it is the default text editor for GNOME.

Released under the terms of the GNU General Public License, gedit is free software.

Read more about Gedit:  Features, Architecture