Roundcube - Free and Open Source Webmail Software. Thanks to NSA, one starts to think again whether one does not want to handle mail oneself. Ok, one really does not want to, because sorting spam is no fun, but well, if one does want to, this might be a somewhat more modern variant of webmail solutions. In addition, one can integrate it into Owncloud via an app. Although this is really just an iframe integration - so do not expect to be able to use your address book together or something like that. Personally, I will probably stick with pushing my mail through Google and letting the NSA sort my spam. But contacts and calendars could soon end up on my owncloud. Even the file sync has become really good in the latest versions.