Gaia Sky WebGL version
The Gaia Sky software, former Gaia Sandbox, (and in particular its WebGL ports) has been chosen by ESA to be Gaia Image of the Week. The WebGL version includes a spinoff –called A Window to Gaia: The Focal Plane – which displays in real time the Tycho-2 stars that are being observed by Gaia. The WebGL ports have problems with mobile browsers and also with Safari, but they should work well with Google Chrome and Firefox (the former is significantly faster than the latter).
Here is the video which showcases the web applications: