BitTorrent Sync is a Dropbox-like app that syncs a folder between distributed peers, rather than using a central cloud server. It supports shared folders with read-only as well as read-write permissions.
Update (2013-05-02): Unfortunately, it doesn’t sync extended attributes (xattrs) or Mac metadata.
BitTorrent Cloud Dropbox Extended Attributes Syncing
Brian Greenstone’s book is now available as a free PDF download (via Peter Hosey). I remember enjoying it when it came out around the Panther timeframe. There’s probably still some relevant information in it, amidst reference to CHUD, Shark, Sherlock, and the old QuickTime APIs.
Book C Programming Language Mac OpenGL Programming
