Similar to Elasticsearch

Apache Velocity

Aufs

Axiom (computer algebra system)

Brackets (text editor)

Progress Chef

CodeLite

Concurrent Versions System

Cygwin

Cygwin/X

Darik's Boot and Nuke

Das U-Boot

Distcc

Drupal

DSpace

Eclipse (software)

Enigmail

Erlang (programming language)

Etherpad

Filesystem in Userspace

Free Pascal

GNUmed

ChromeOS

Google Native Client

GPhoto

GThumb

H2 Database Engine

Hibernate (framework)