Pretty much that's how you have to do it with VFP as most of the source files are binary (forms, class libs, reports) and can't use the merge tool of the source control system, which only works on text files. FYI, this merge is not automatic. The developer is presented with two windows, one version in each, and he then determines what need to be added merged.

As for the number of versions, it's really up to you how may you need to patch and keep going. We may have three or four in use by our customers. If we determine that a bug requires a patch, we then determine which versions need it, and patch accordingly. Customers may or may not be notified, as the bug may not affect all. At some point, all customers are required to upgrade to some new release, typically an x.0 release.

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>Using your example above I assume there would be 4 versions of source code in all. Now the big question: are each of these maintained (i.e. fix code manually added to each) separately?
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>cheers