Ubuntu Software Center or simply Software Center is a high-level graphical front end for the APT/dpkg package management system. It is free software written in Python, PyGTK/PyGObject based on GTK+ and the further development of the GNOME application, gnome-app-install.The program can be used to add and manage repositories as well as Ubuntu Personal Package Archives (PPA) and on Ubuntu, the Ubuntu Software Center also allows users to purchase commercial applications.