1. A method for monitoring updates in a software repository in a multi-author software design environment, comprising: constructing a first snapshot of a set of software module source code stored by the software repository at a first point in time, the source code represented by a plurality of objects; constructing a second snapshot of the set of software module source code stored by the software repository at a second point in time; comparing the first snapshot with the second snapshot, to detect differences in the source code; rating each detected difference according to a backward compatibility metric, the backward compatibility metric representing a probability that the detected difference renders a source code attribute of the second snapshot incompatible with a similar source code attribute of the first snapshot; determining an overall backward compatibility score for the second snapshot, based on the rated differences; and issuing an alert message to registered authors of the set of software module source code when the overall backward compatibility exceeds a backward compatibility threshold, wherein the alert message is issued only to users associated with objects for which differences are detected.