On Thursday the development team released the first release candidate for Serendipity 2.1. Many things has been improved and S9Y is now ready for PHP7. As stated in the official blogpost, 2.1 focuses on

• Rewrites in some older legacy parts of the core (URL routing, template fallback chain, experimental internal caching) as well as PHP7 compatibility.
• New bundled responsive themes "Timeline" and "Clean-Blog"
• Improved usability of plugin upgrades by combining sidebar and event plugins and upgrading multiple plugins at once
• Permission checks for the dashboard output and comments
• Usability improvements to the media library, bulk moving support
• New API wrapper for URL downloads that plugins can use (serendipity_request_url)
• New Theme "Skeleton" (responsive, mobile first)
• Improved preview iframe handling
• Changes (simplifications) in template file routing for backend/frontend views, new smarty {getFile} function for theme authors
• (new for rc1) Ability to set a default posting category for an author
• (new for rc1) Improved security checks against CSRF attacks (comment moderation, comment toggling
• (new for rc1) Improved security for referrer redirection
• (new for rc1) Improved security for local file hotlinking
• (new for rc1) Fixed sorting media database by filename

I'm very happy to see this RC because we all waited a long time for this version step.

One point for you guys who install this TC: There is a small bug: The Upgrade-Button in the plugin-section is not working (you will get the HTTP-Referrer error message, since a token is missing). This is the fix and would need to be manually applied.