The Sony Ericsson P900 is a Symbian OS v7.0 based smartphone from Sony Ericsson. It was introduced in 2003 and is the successor of the Sony Ericsson P800, and, like the P800 uses the UIQ platform. Like other Symbian-based smartphones, the P900 is an open phone, which means that it is possible to develop and install third party applications without restrictions. A UIQ 2.1 SDK based upon Symbian C++ is freely available from the Sony Ericsson developer website . Additionally, the P900 supports applications written in Java. Because of this openness, a great number of third-party applications exist that can be used on the P900 and other UIQ phones (such as the Motorola A1000 and BenQ P30). Many are shareware and freeware.