The Phoenix event display framework

<!--HTML-->Visualising HEP experiment event data and geometry is vital for physicists trying to debug their reconstruction software, their detector geometry or their physics analysis, and also for outreach and publicity purposes. Traditionally experiments used in-house applications that required installation (often as part of a much larger experiment specific framework). In recent years, web-based event/geometry displays have started to appear, dramatically lowering the entry barrier to use, but which typically are still per-experiment. The Phoenix framework is an extensible, experiment-agnostic framework for event and geometry visualisation.