LiveTraffic is a plugin for the flight simulator X-Plane to show real-life traffic, based on publicly available live flight data, as additional planes within X-Plane.
Long queues at KLAS, 07-JAN-2019, 14:42
It came into being when I was looking at plugins simulating additional traffic in X-Plane and thinking at that time: Why do they try to simulate traffic and invent flight models when there is flight data available online which brings yet another piece of reality into the simulation? Why can't one just read the data and display the aircraft?
Well...turned out it's not that easy
I spent an awful lot of time dealing with the inaccuracies of the data sources, see Limitations. There are only timestamps and positions. Heading and speed is point-in-time info but not a reliable vector to the next position. There is no information on pitch or bank angle, or on gear or flaps positions. There is no info where exactly a plane touched or left ground. There are several data feeders, which aren't in synch and contradict each other.
So I ended up inventing my own flight models to make aircraft move more or less smoothly from one data point to the next, extend gear and flaps, pitch up an down, flare, rotate etc.
Because an airport is a naturally interesting hot spot of plane movements, but due to simple physics often only sparingly covered with ADS-B receivers and hence live data, there is even lots of code to simulate final approach, landing, and roll-out for planes for which data coverage ends during approach.
There is extensive "data cleansing", which removes up to half the data...and many thanks here to "my" beta testers, who spent hours to find, test out, and document hot spots of inaccuracies in the world!
If you do all that already, then remember that there are a lot of people in the world having a completely different set of problems than seeking simulated live traffic in a flight simulator. This is an organization I can recommend: