James Cherkoff wonders (in a comment) if my common platform isn’t really just… well… the web. It’s a good question because the web, of course, is the mother-and-father of all platforms, a place with such a richness of tools and outlets that it might seem as if it has no need of an additional layer like a common platform. But I think the answer to James’ question really is ‘no’.
The Common Platform (see, it’s already acquired a ‘The’ and Capital Letters like it’s a real thing!) is a designed overlay for the web, an elaboration. The sort of secondary functionality that all platforms sooner-or-later acquire. That’s not to say that it’s separate from or outside the web proper (not a walled garden or a locked-down proprietary thing). In fact it’s strength will lie in the fact that it is profoundly of the web.
Trying to be as ‘web-like’ as possible here I can imagine a common platform, at its simplest, as barely more than a commissioning model plus a tag-cloud. At its largest and most monolithic… It shouldn’t really be large or monolithic.
Expanding on this slightly, the Common Platform should be an organisational device plus some commissioning logic plus some kind of resource discovery gubbins and a wafer of UI to point all the different stakeholders at what they need. Bob’s Your Uncle. Job done. Public service media transformed. Next!