Description: OpenStreetMap is a free, open-source, crowd-sourced map of the world. Volunteers collect map data using GPS devices, aerial imagery, local knowledge, and other free sources to create and update the map database.
Type: software
Pricing: Open Source
Description: Stack Overflow is a popular question and answer site for programmers. Users can ask coding questions and receive answers from a community of developers. The site has a reputation system to rate helpful responses.
Type: software
Pricing: Subscription