OpenGrok is a fast and usable source code search and cross reference engine.
It helps you search, cross-reference and navigate your source tree. It can
understand various program file formats and version control histories like
SCCS, RCS, CVS and Subversion. In other words it lets you grok (profoundly
understand) the open source, hence the name OpenGrok. It is written in Java.

With this package, OpenGrok is built from source.