Programs for Browsing Source Code

Source Insight: At most can be used for free for 1 month. What's more there is no coresponding version on Linux.

lxr[1]: A general purpose source code indexer and cross-referencer that provides web-based browsing of source code with links to the definition and usage of any identifier. Supports multiple languages.

hypersrc[2]: An open-source (GNU GPL) GUI program for browsing source code. It displays a list of sorted source code tags and a tree view of functions. You can click a tag to hyperlink to its line in a source code file. hypersrc uses Exuberant ctags which supports 33 programming languages though hypersrc additionally supports FORTH and M4.

Glimpse[3]: A very powerful indexing and query system that allows you to search through all your files very quickly. It can be used by individuals for their personal file systems as well as by organizations for large data collections. Glimpse is also the basis of WebGlimpse, which provides search for web sites, and it is the default search engine in Harvest.

vim+ctags/cscope: Hard to use.

[1] http://sourceforge.net/projects/lxr
[2] http://www.jimbrooks.org/web/hypersrc/hypersrc.php
[3]http://webglimpse.net/subfeatures/features.html