Description: ForgeMtG is an open source Magic: The Gathering simulator and deck editor that lets you build and test decks, play against AI opponents or other players online, and more. It offers a robust rules engine and card database for free.
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