GpsPrune is an application for viewing, editing and converting coordinate data from GPS systems. Basically it's a tool to let you play with your GPS data after you get home from your trip.
GpsPrune screenshot

Screenshot from a Linux system showing
the map view and altitude profile

It can load data from arbitrary text-based formats (for example, any tab-separated or comma-separated file) or Xml, or directly from a GPS receiver. It can display the data (as map view using openstreetmap images and as altitude

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps. Weighing just about 38 KB of JS, it has all the mapping features most developers ever need.