Vim

Vim is a compact program that is designed as a simple text editor but has a lot of extra features waiting under the hood. The application was created to handle code and can do a lot more than just writing an email or opening a configuration file.
It allows you to edit text and to save simple text files but its main function is to assist with code editing. It supports syntax highlighting and row numbering, two functions that are essential for any programmer. The users that write code for hours can change the color scheme of the interface in order to increase the code visibility.
For text editing the program includes a spell checker with multiple languages and the ability to suggest corrections for the spelling mistakes. This can also come in handy even when you are writing code since the application only checks the text that is not recognized as code. You can also quickly jump from one error to the next in order to proofread the text.
The application can recognize plenty of programming languages and allows you to set the syntax manually. You can use this tool to convert a simple text to HTML or to hexadecimal code with just one click.
If you usually work with many documents simultaneously the program can accommodate your style by opening multiple files in the same window. You can also split the current window and view two instances of the document that you are working on. This is useful when you work with large files and you need to view a certain part of the code while writing new lines.
The interface of the app seems similar to a basic text editor until you click on a menu and all the functions are revealed. Although it is not as easy to understand by the average computer user, a seasoned developer can easily navigate through the menus and make use of the program's features.
Although you can use the program as a simple text editor, Vim is clearly aimed at programmers and developers. If you just need to write a note, there are simpler solutions out there.