The Arduino IDE is a very good tool when you are learning to develop for AVR family of microcontrollers, but it becomes a barrier to more structured projects. In view of these difficulties it was decided to create a tool to automate the creation and maintenance of projects.
The sketchduino will create a complete project, a project will be created with the following structure:
binary (result of compile processes) lib (custom libraries of projetct future) include (custom libraries of projetct future) src (the code of you project) tmp (temporary files of processes of compiler)