Pervasive computing is nowadays becoming a reality, exploiting the capabilities offered by both computing infrastructure and communication facilities. The pervasive computing environment encompasses a multitude of diverse devices, operating systems, protocols, and standards. It includes mobile devices such as cellular phones, smart phones, PDAs, and handheld computers for information access, smart cards, and smart labels for identification and authentication, smart sensors, and actuators that perceive the surroundings and react accordingly. Voice technologies such as automatic speech recognition (ASR), text to speech (TTS) and VoiceXML enable the construction of convenient user interfaces and Web services are a key mechanism for interoperability. Wireless wide area networking allows long distance communication through cellular radio while wireless local and personal area networking and standards such as the Wi-Fi, Bluetooth and IrDA allow short distance communication through radio waves and infrared beams. In the mobile and pervasive computing environment, software engineering should not treat diversity and mobility as problems to overcome, but seek methods of which it could take advantage instead. In these environments, the selection of purpose-oriented and timely information, tailored to user preferences and media characteristics will ensure optimised information delivery. To this end, the context—the information that surrounds the human-computer interaction—plays a key role and is rapidly changing in mobile settings, and the understanding of it is indispensable for application designers in order to choose, capture and exploit it. The importance of the context is to use it to make context-aware applications, that is, those applications that are interested in who, where, when and what, in order to determine why the situation occurs and adapt their behavior accordingly.