Methods and apparatus, including computer program products, for context-aware and real-time tracking of articles. In one aspect, a method includes: receiving multiple instances of tag-read-data, each instance including information read automatically from a tag bound to an article, each instance also including status information including a location of the tag and article; receiving one or more instances of context information, each instance describing an associated non-taggable physical circumstance, the context information indicating a status including a location of the circumstance, the multiple instances of context information collectively including information describing multiple circumstances; using the received tag-read-data and context information to maintain physical objects and context objects in a virtual world, the physical objects representing the articles and the context objects representing the circumstances; and detecting interactions in the virtual world between the circumstances and the articles.