The rapidly growing amount of semantically represented data on the Web creates the need for more intuitive methods and tools to interact with these data and to use them in standard Web applications. We present a method how users can interactively define personalized views of large semantic data spaces. Specifically, we propose X3S as a technique and format for specifying ‘semantic widgets’ that integrate querying and filtering of semantic data with defining their layout and presentation style. In addition, an editor has been developed that allows to create X3S templates in a direct manipulation style. The editor and the underlying format are evaluated against existing approaches by comparing their functional capabilities as well as in an initial user study.