I'm doing some analysis of .gpx files, and I realise that knowing two points (latitude, longitude) on the Earth's surface doesn't tell you the distance between them. For that you need a formula (algorithm). A popular one which is fairly accurate for short distances is Haversine. If you don't mind telling me, which algorithm does the Web Editor use? I can't make my distances the same as yours - they are out by quite a large margin, so I'm curious to know.
thanks for any info