Wireless communications technologies are the platform to develop user-centric systems in a multi-device platform that allows mobility and user-friendly interaction. The development of a multi-device platform requires a common language such as Java. This book discusses two different works related with Bluetooth and GPS-GSM communication, to illustrate the capacity of Java language to develop applications that need wireless communications. Java application on the distributed system is introduced by certain keywords, design pattern, software architecture, design process and architecture for ubiquitous space. Furthermore, Java is often used as an embedded programming system, which is a combination of hardware, software, mechanical and other technical components designed to perform a dedicated function, unlike a general purposes computer. This book describes a new development framework for embedded control systems and engine calibration is presented, which supports the modelling of such systems and provides tools for the design and validation activities. An analytical method to express the resonant frequency in terms of the lumped component values is outlined as well.