Smultron is a text editor for Mac OS X that is designed for both beginners and advanced users; it was originally published as open source and is now sold through the Mac App Store It is written in Objective-C using the Cocoa API. It is able to edit and save many different file types, and has syntax highlighting support for many popular programming languages including C, C++, LISP, Java, Python, PHP, Ruby, HTML, XML, CSS, Prolog, IDL and D.