* Search engine: http://www.seeks-project.info/, https://github.com/asciimoo/searx
* Maps: https://github.com/MapBBCode/share.mapbbcode.org/, https://github.com/Project-OSRM/osrm-backend/ (routing, hard to setup)
* Mail: https://roundcube.net, http://rainloop.net, https://www.mailpile.is/ (the hard part is getting the mail server right)
* Media: https://github.com/sebsauvage/minigalnano (FTP/SSH upload only), http://mediagoblin.org/
See something missing?