The Internet brings many new features to the process control and automation field however it has its limitations in terms of functionality, performance, security, and reliability. Emerging Web technologies are promising to overcome many of these limitations, and are helping the Internet to evolve into a highly graphical, interactive and collaborative environment. The objective of this paper was to investigate the design and application of an Internet-based SCADA system using Java and XML. This is tested by two projects: the first uses a lab-scale Java-based control system to control a typical process control application. The second extends the preceding work to show, in standard unified modelling language (UML) notation, how separate control systems can be integrated with each other, using Java and XML, to achieve a wider distributed control function.