by Robert Cowham, Brad Appleton and Steve Berczuk

Branching is a mechanism for isolation and parallel development which is useful in many situations as discussed below. The advantage of branching with good tool support is that it allows you to merge changes between branches more easily, and in a less error prone manner than manually making the same code changes to the two separate branches (see Introduction to Branching from Streamed Lines).

There is little lasting value in branching if the branches will diverge indefinitely without propagating any changes. It may be seen as a short-term win that allows a new project to get up and running very quickly from an existing codebase for another product. But the gains of such persistent variants are very short-term, and the resulting long-term costs of proliferating code and effort across the same codebase can quickly overwhelm whatever short-term gain is to be had.