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; like the P800, the P900 uses the UIQ platform. Like other Symbian-based smartphones of its time, but unlike Ericsson R380, the P900 is an open phone. This 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, many 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.