What Estela is built on
Other people's work, named. Most of what makes this app private is a decision to hold a copy of something rather than call a service for it, which only works because these were given away.
The place index, 170,540 towns, cities and regions. Every search you make runs against a copy of it on this server, so that no outside service ever learns what you were looking for.
The coastlines on the Atlas, at 1:110m. Drawn here rather than fetched as map tiles, for the same reason.
Where the Sun, Moon and planets were. Produced by the Jet Propulsion Laboratory at Caltech for NASA.
Reads the ephemeris and turns it into positions. By Brandon Rhodes.
Holds everything, and enforces the rules that matter at the database rather than trusting the app to remember them.
The application itself.
Place data from GeoNames is used under CC BY 4.0 and has been extracted and reformatted for search. Nothing here is endorsed by any of the above.