Point 6: VISTA's Software Stream Has Many Tributaries, Part 2

Dear Reader,

. . . Continued from part one yesterday.

Although it hasn't happened much for the last fifteen years, a vital part of this software stream is that every year or two each package should release a fresh version of their entire package, an upgrade that goes through a more intense re-engineering, documentation, testing, and verification cycle than patches get. This helps keep each package's architecture fresh and provides a deep housecleaning period to flush out the subtler or more intractable bugs. So, the "patch stream" is actually a software stream that includes both patches and new versions.

So what about complete snapshots of VISTA? Most software in the world is managed by releasing entire new snapshots. What about VISTA?

Well, this is part of where the VISTA lifecycle turns everyone's expectations on their head, part of why our software lifecycle doesn't begin with a single code repository. Nobody upgrades VISTA with a complete snapshot. VISTA's code and data are and must be far too intricately intertwined to simply swap out all the code like most software does. Instead, we upgrade with incremental changes, with patches and new versions of individual packages. At best, VISTA snapshots are useful for starting a brand-new VISTA system from scratch.

Even if VISTA weren't so vast as to be unmanageable as a single codebase, this is the other reason we do not begin the software stream with a single code repository - because most VISTA adopters have little use for new snapshots. Instead of being the source of the stream, the VISTA platinum account (the clean and shiny VISTA codebase from which snapshots are created) is just another recipient of the software stream at the end of one of its delta channels, like any other VISTA system. That is, the platinum code repository is a recipient, not the source, of the software stream. It has to be.

VISTA can only be managed piecemeal, with all its separate threads of user feedback and incremental changes being woven through Forum to create the fabric of VISTA.

Yours truly,
Rick