Gedit, gnome’s standard light-weight text editor has extensions available in the repositories.
To install them, open a terminal and copy/paste the following command:
sudo apt-get install gedit-plugins
The following features are added to gedit:
* Show/Hide Tabbar: Add a menu entry to show/hide the tabbar.
* Bracket Completion: Automatically adds closing brackets.
* Draw Spaces: Draw Spaces and Tabs
* Embedded Terminal: Embed a terminal in the bottom pane.
* Color Picker: Pick a color from a dialog and insert its hexadecimal representation.
* Session Saver: Save and restore your working sessions
* Join/Split Lines: Join several lines or split long ones
* Smart Spaces: Forget you’re not using tabulations.
* Character Map: Insert special characters just by clicking on them.
* Code comment: Comment out or uncomment a selected block of code.
Third-party add-ons (not officially supported) can be found here.