Notepad++ is a free source editor and Notepad replacement with the syntax highlighting.
It also gives the extra functionality to the general user: colorize the user defined words. You can print your source code in color (or whatever you want) if you have a color printer (WYSIWYG). Furthermore, Notepad++ includes the multi-view feature, which allows the user to edit the different documents at the same time, and even edit the same document synchronously in 2 different views. Notepad++ supports drag and drop: not only you can drop the file from explorer to open it, but also you can drag and drop a document from a view to another. With all the functionalities, Notepad++ runs as fast as Notepad provided by MS Windows.