When talking about the power of open formats, discussion generally gravitates to one of two ends of the same spectrum:

1. SMTP, which by all accounts has been a roaring and smashing success story (so long as you ignore the fact that Gmail is for all intents and purposes a benevolent dictator in the space) in no small part because the mechanics of "using the protocol" is abstracted away from the end user.
2. RSS, which is extremely powerful and useful as a medium but has largely failed as a consumer-facing technology in part because it demands, at some level, an understanding of the underlying technology. (We do not call Mimestream an "SMTP client"; we do call Feedbin an "RSS reader.")

Nestled somewhere in between the two is ICS. ICS has a handful of interesting characteristics:

• It is a protocol that has, for all intents and purposes, won. Every major calendar app is backed by ICS.
• It's an extremely simple and portable protocol. It's a little janky (XML is underrated!) but it's plain-text and easy to parse in any language or context.
• Everyone uses ICS; very few people who own iPhones don't use their Calendar app.

And yet there's very little discussion about ICS. It doesn't feel like a lot of people are experimenting with it as a form or surface, despite distribution being easy (if you have a useful ICS, every single person on the planet can use it with an app they already have in a single click) and production being easy (again, it's just a text file, which is trivial to generate). The obvious answer is "well, there's not that much stuff to do with a calendar" — I reject this. I think we (or perhaps just I) think about the world through a temporal lens; one can imagine a world where people treat calendar apps as more of a B2B application. A calendar showing every deploy and every incident; a calendar showing every new registration and new churn. Calendar apps have done a lot of shared work in terms of filtering and collating "events" that seem naturally extensible to non-personal use cases.

All of this is prelude to the fact that I am, to a certain extent, talking my book: I just built a small little converter from ICS to RSS, arguably the opposite of what I'm espousing above. (If you're looking for the inverse operation, I recommend rsstocal, a tool with an equally creative name.) But I am thinking a lot about calendars these days, and where they might be useful in ways hitherto unconsidered.