This is really part of issue #781, but it's the part that might want to go into 1.0. Here is a repeat of my comments of Mon Dec 15 13:28:26 -0800 2003 from that issue: This is item #3 from Greg Hudson's list of API changes to solve for 1.0, in thread http://subversion.tigris.org/servlets/BrowseList?list=dev&by=thread&from=139821 I expressed skepticism that we should tackle this before 1.0, because it might involve a long discussion, and Greg responded in http://subversion.tigris.org/servlets/ReadMsg?list=dev&msgNo=52339 saying I think we will find (either the hard way or the easy way) that after 1.0, API changes have to be batched up and made at rare intervals--like, every five years or so. We'll need to develop ways for people to have old and new versions of Subversion installed on the same system, and we'll have to write special documentation to help people transition to the new API. So, if we want to support new features without a lot of pain, we either have to do it without breaking backward compatibility (i.e. adding new functions, but preserving old ones) or we have to anticipate them now. Discussion continues.