This week, computer scientists from Microsoft Research will unveil a new design for an operating system and a browser built to withstand the growing security threats of the Web. Though the projects—ServiceOS and the Gazelle Web browser—are far from becoming commercial products, they provide insight into how Microsoft views the evolution of PC software.

Helen Wang, a senior researcher, will present two papers on the designs at the USENIX Security Symposium this week. Wang says her work and the work of her colleagues is intended to address a “paradigm shift” in how PCs are used. People are increasingly dependent on their digital devices, and they are much more likely to use Web applications for .........