I just released SabreDAV 1.7, after about 7 months of work. A lot of work has gone into optimizing operations, and a bunch of new features have been added. I also stopped supporting the PEAR packages, and fully migrated to composer. If you download the zip, the required composer files are actually shipped along.

SabreDAV's uptake and contributions has also been very encouraging. This is especially nice since it solves such a niche problem :).

Most relevant new stuff:

• A bunch of REPORT queries got a lot faster. Especially some CalDAV-related requests can be exponentially faster. Some larger operations sped up from several minutes, to several seconds.
• The VObject library has spun off into a separate project: sabre-vobject.
• Experimental support for caldav-sharing and caldav-notifications.
• Added a VCFExportPlugin, similar to the ICSExportPlugin.
• Added a bunch of free-busy reports that now make it possible for iCal to use them.
• Added support for a PATCH format for binary updates
• Switched to using the Composer autoloader.
• Stronger validation of both iCalendar and vCard files.
• Support for Brief and Prefer: return-minimal headers.

Some links

• Full changelog
• Upgrade instructions
• Composer package
• Zip download

A big thank you to everybody involved!