A simple web app that shows the position of the international space station (ISS):
TLEs are downloaded from Celestrak when the application is started. The image is generated on the server, the page refreshes it every two seconds.
This is just a fun project I decided to do after reading Diary of an Apprentice Astronaut by Samantha Cristoforetti. Rendering the map on the server every two seconds is quite inefficient and some features are missing, e.g. reloading the TLE file periodically.
A lot more information about the ISS, its orbit, at what time it can be seen in the sky, can be found on the Heavens-Above webpage.
The default port is 8080. A different port can be specified on the command line, e.g.
$ ./issposition 1234