JHelioviewer is an open-source project started by the European Space Agency in 2009. It allows researchers to combine data from many solar instruments and display images and metadata in 2D and 3D. Originally, JHelioviewer was developed to enable researchers to browse the vast data set of 1.5TB per day collected by the Solar Dynamics Observatory (SDO) and combine them with other instruments.

Quickly loading and visualizing the enormous data sets is the big challenge in JHelioviewer. Researchers do not want to wait unnecessarily, and they expect a friendly user interface. To achieve that, Ateleris team members improved JHelioviewer by refactoring the code base altogether. During this process, the code shrunk to less than half its original size. These efforts led to a drastic reduction of known bugs, improved performance, and simplified implementation of new ideas.