Other software, such as GNU LilyPond and Philip's Music Writer, reads input from ordinary text files whose contents resemble a computer macro programming language that describes bare musical content with little or no layout specification. The software translates the usually handwritten description into fully engraved graphical pages to view or send for printing, taking care of appearance decisions from high level layout down to glyph drawing. The music entry process is iterative and is similar to the edit-compile-execute cycle used to debug computer programs.