A couple of us at Mozilla have been trying to figure out how to revive activities/intents for the web. Both work relatively well in closed environments such as Firefox OS and Android, but seem harder to deploy in a generic way on the web.
What we've been looking at instead is solving a smaller use case. A Sharing API to start and then hopefully reuse the building blocks for other features that need to be liberated. https://wiki.whatwg.org/wiki/Sharing/API has a sketch for what a very minimal Sharing API could look like. Our thinking is that something like the overlay browsing context could be reused to make e.g. <input type=file> or "save as" extensible going forward. However, admittedly it still doesn't really click. It feels a bit too much like e.g. the various search extensions browsers offer. Too much work for little return. Furthermore, freeing the web somehow from closely knitted silos seems like a worthwhile goal, but is often counter to what those silos are interested in. So it might be that we're still not quite there yet, thoughts appreciated. (I put WebApps and TAG on bcc, hope that's okay.) -- https://annevankesteren.nl/
