Google Maps is a web mapping service. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bicycle and air, or public transportation.
ASP.NET is an open-source, server-side web-application framework designed for web development to produce dynamic web pages.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.