A large dataset that contains the eye movements of N=216 programmers of different experience levels captured during two code comprehension tasks is presented. Data are grouped in terms of programming expertise (from none to high) and other demographic descriptors. Data were collected through an international collaborative effort that involved eleven research teams across eight countries on four continents. The same eye tracking apparatus and software was used for the data collection. The Eye Movements in Programming (EMIP) dataset is freely available for download. The varied metadata in the EMIP dataset provides fertile ground for the analysis of gaze behavior and may be used to make novel insights about code comprehension.

The XS-2 system that integrates specification, rapid prototyping, and the actual use of application dialogs is described. The XS-2 command language grammar, a nonprocedural description language based on regular expressions, is used to specify commands for any application program. The syntax of the command specification is visible to the user: command names and their activation rules are displayed as a command tree. Since a small set of tools is provided for the development of the command specification and its automatic translation into a prototype application module in Modula-2, no programming work is necessary to design and evaluate the commands. Experience shows that an advanced end user can develop his or her own prototype application without a programmer's assistance.>