43 Things is a social networking website established as an online goal setting community. It is built on the principles of tagging, rather than creating explicit interpersonal links (as seen in Friendster and Orkut). Users create accounts and then list a number of goals or hopes; these goals are parsed by a lexer and connected to other people's goals that are constructed with similar words or ideas. This concept is also known as folksonomy. Users can set up to 43 goals, and are encouraged to explore the lists of other users and "cheer" them on towards achieving their goals.
Java is a general-purpose, concurrent, class-based, object-oriented computer programming language that is specifically designed to have as few implementation dependencies as possible. It is intended to let application developers "write once, run anywhere" (WORA), meaning that code that runs on one platform does not need to be recompiled to run on another.
An open source license is a copyright license for computer software that allows the source code to be freely, that is by anyone for any purpose, used, modified and shared. This allows end users to review and modify the source code for their own customization, curiosity or troubleshooting needs.