Sourcegraph - Sourcegraph is a free, self-hosted code search and intelligence server that helps developers find, review, understand, and debug code. Use it with any Git code host for teams from 1 to 10,000+.

GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab

Atlassian Fisheye - With FishEye you can search code, visualize and report on activity and find for commits, files, revisions, or teammates across SVN, Git, Mercurial, CVS and Perforce.

GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.

Krugle - Krugle is the complete enterprise solution for search targeted to the development organization. 

GitList - GitList allows you to browse repositories using your favorite browser, viewing files under...