Originally Posted by http://notepad-plus.sourceforge.net/uk/site.htm
Based on a powerful editing component Scintilla, Notepad++ is written in C++1 and uses pure Win32 API and STL2 which ensures a higher execution speed3 and smaller program size4. By optimizing as many routines as possible without losing user friendlyness, Notepad++ is trying to reduce the world carbon dioxide emissions. When using less CPU power, the PC can throttle down and reduce power consumption, resulting in a greener environment.5