Ajax
Asynchronous JavaScript + XML:
standards-based presentation using XHTML and CSS; dynamic display and interaction using the Document Object Model; data interchange and manipulation using XML and XSLT; asynchronous data retrieval using XMLHttpRequest; and JavaScript binding everything together.
-Jesse James Garrett
Git
A distributed revision control and source code management (SCM) system with 30% adoption. Linus Torvalds, 2005
GitHub
A web-based hosting service for software development projects that use the Git revision control system. Launched 2008. Alexa rank 206