Code Duet - Finding a partner for pair-programming in 5 minutes

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+.

One Degree - The Human Search Engine

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.

Keyory - Schedule periodic emails and get aggregated responses delivered right to your inbox with Keyory.

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