Storm
github.com/nathanmarz/storm
Repository
nathanmarz/storm
Distributed and fault-tolerant realtime computation: stream processing, continuous computation, distributed RPC, and more
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Storm is a distributed realtime computation system. Similar to how Hadoop provides a set of general primitives for doing batch processing, Storm provides a set of general primitives for doing realtime computation. Storm is simple, can be used with any programming language, and is a lot of fun to use!