The Simple Internet Version Control protocol (SIVC - pronounced "civic") is a system intended to help people on the Internet keep their software up-to-date, while providing software developers with good estimations of their products' Internet user bases. While interesting to all developers, these estimations are particularly useful to developers of public domain, freeware and shareware products since the size of a product's user base is often a major factor in justifying continued development. In addition, SIVC can reduce product support demands, and improve user experiences, by helping to ensure that users have current versions of their SIVC-equipped software.
AUTHOR'S NOTE: While all the SIVC software and source code is currently available only for Macintoshes, that's simply because I happen to be a Macintosh programmer (same thing for the other early adopters thus far). There is nothing Mac-specific about the protocol. No matter what computing platform your SIVC software runs on, I'd like to know about it, so it can be publicized here. There's no platform bias here.