Apple's OpenDoc [1] was another attempt to break out of the silos of monolithic apps each completely responsible for their own document formats. It died. I do

Apple's OpenDoc [1] was another attempt to break out of the silos of monolithic apps each completely responsible for their own document formats. It died. I don't think there are any real technical of programming language challenges to making this work. It's a problem of economics and sociology. Economics: If your doc/app/thing is composed of a multitude of widgets developed by different developers, who pays for those widgets to be developed? If you have to buy them, does that mean you get a doc that you can't send to anyone else unless they have they've paid for the same widgets? (This problems exists today in the world of music production where there is a thriving plug-in model of third-party VSTs which are wonderful for extensibility but do make it quite hard to share projects with people.) If that's not the business model... what is? I don't think anyone ever figured out a good way to make money making software like this outside of limited domains. Sociology: Conway's law [2] isn't a joke. It's a real observation that for different software components to interoperate, the teams making them need to communicate at least enough to create protocols. Defining software protocols that are expressive enough to be useful but simple and stable enough to be widely used by completely independent competing organizations is really hard. Imagine you had to design an API for composable UI widgets. How would you handle text rendering? RTL? Theming? Colors? Layout? It's not intractable, but it's not far from it. Both: Then you have to consider that if you have competing organizations trying to make money selling widgets, they don't want their competitors widgets to be successful. They are incentivized to undermine compositionality whenever they can (Microsoft's old "Embrace, extend, and extinguish" [3]). Also, a fundamental tenet of usability is that the interface as a whole should be consistent and hang together. Users don't want apps that are a patchwork of jarring widgets each with its own style and convention. If you could get a platform like this off the ground, users would still like converge onto a small number of companies that made large sets of widget suites that are designed to compose together harmoniously. The usability benefits of doing so would work like network effects to lead towards platform consolidation. Software people just dramatically underestimate how hard composability actually is in practice. It doesn't matter if you can shuffle bits between two pieces of code. That's the easy part. The hard parts are all in protocol design, usability, competition, etc. [1]: https://en.wikipedia.org/wiki/OpenDoc https://en.wikipedia.org/wiki/OpenDoc [2]: https://en.wikipedia.org/wiki/Conway%27s_law https://en.wikipedia.org/wiki/Conway%27s_law [3]: https://en.wikipedia.org/wiki/Embrace,_extend,_and_extinguish https://en.wikipedia.org/wiki/Embrace,_extend,_and_extinguis...