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+.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
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.
wikiHow - wikiHow is a wiki based collaboration to build the world’s largest, highest quality how to manual.
Krugle - Krugle is the complete enterprise solution for search targeted to the development organization.
AllAnswered - Your Team's Collective Brain All-In-One Knowledge Management System Wiki + Q&A + Workflow + AI