MIDP applications are called MIDlets. Like applets or servlets, MIDlets have a specific life cycle; they are managed by device software. This chapter details the entries that may be in the MIDlet suite manifest file and the application descriptor. Application properties can be used as a way to store information in the application descriptor instead of hard-coding values into the MIDlet source code. A tool like the J2ME Wireless Toolkit automatically handles many of the details of MIDlet attributes packaging. MIDP 2.0 includes a comprehensive security architecture based on protection domains.