Social Stream Presence is a bridge to an XMPP server. It has a client integrated with the web, but also can be used with an external XMPP client. Though it is distributed with Social Stream, it would not work until the presence-related configuration is done. Take a look at the Getting Started With Social Stream Presence wiki page.
This version brings integrated i18n support. Browser language settings are recognized automatically. Users can also set their preferred language in their settings page. This is contribution is from Raquel, one of our two new core developer members; Raquel and Rafael have started with power with valuable contributions to this version of Social Stream.
0.17.0 also comes with an important migration in the core: the channel table. One of the most known functionalities Social Stream provides is change session. Users can act in behalf of a group, posting, making contacts and doing any activity as the where the group themselves. Up to date, the user behind the representation was not tracked, which could lead to responsibility problems. The channel table fixes this issue.
Do not forget to migrate the database. Running
rake social_stream:migrations:update will copy all the missing migrations to your application.