The operating system used by BlackBerry devices is a proprietary multitasking environment developed by RIM. The operating system is designed for use of input devices such as the track wheel, track ball, and track pad. The OS provides support for Java MIDP 1.0 and WAP 1.2. Previous versions allowed wireless synchronization with Microsoft Exchange Server e-mail and calendar, as well as with Lotus Domino e-mail. The current OS 5.0 provides a subset of MIDP 2.0, and allows complete wireless activation and synchronization with Exchange e-mail, calendar, tasks, notes and contacts, and adds support for Novell GroupWise and Lotus Notes.
Third-party developers can write software using these APIs, and proprietary BlackBerry APIs as well. Any application that makes use of certain restricted functionality must be digitally signed so that it can be associated to a developer account at RIM. This signing procedure guarantees the authorship of an application but does not guarantee the quality or security of the code. RIM provides tools for developing applications and themes for BlackBerry. Applications and themes can be loaded onto BlackBerry devices through BlackBerry App World, Over The Air (OTA) through the BlackBerry mobile browser, or through BlackBerry Desktop Manager.