Abstract
TOPI (http://se.inf.ethz.ch/events/topi2013/) is a workshop started in 2011 to address research questions involving plug-ins: software components designed and written to execute within an extensible platform. Most such software components are tools meant to be used within a development environment for constructing software. Other environments are middle-ware platforms and web browsers. Research on plug-ins encompasses the characteristics that differentiate them from other types of software, their interactions with each other, and the platforms they extend.