OpenGrok - Fast and usable source code search and cross reference engine, written in Java

OpenGrok is a fast and usable source code search and cross reference engine, written in Java. It helps you search, cross-reference and navigate your source tree. It can understand various program file formats and version control histories of many source code management systems.

It can search for full text, definitions, symbols, path and revision history, Search query with Google like syntax, incrementally update its index. i.e update only the changed files since last time it was updated. It also provides a read-only web interface for version control systems like Mercurial, CVS, SVN, SCCS or TeamWare.