JMAP for Calendars, Contacts and Files Now in Stalwart

While JMAP seems to scratch every itch of a sucker for proper web API design, I’m wondering if the design space for new protocols should really be constrained to layers on top of HTTP. Is there really any new-ish binary protocol these days? Stuff like file sharing or groupware, mail, calendars, and so on—these things could be a lot more efficient and don’t really need the overhead of JSON as the message interchange format, IMHO. Then again, a lot of solid thinking went into these things, so there probably are a lot of good reasons that I’m not aware of.

Still, it’s an interesting space, I think.

> binary protocol

Email was never a binary protocol. Notoriously so, it's why MIME types and MIME encodings get so complicated.

Most of the "old internet" protocols (email, FTP, even HTTP itself) were bootstrapped on top of built-mostly-for-plaintext Telnet. HTTP as the new telnet has a bunch of improvements when it comes to binary data, request/response-based data flows, and some other considerations. HTTP/3 is even inherently a binary protocol, it's lack of "telnet-compatibility" one of the concerns about switching the majority of the web to it.

vCard/vCal/iCard/iCal were also deeply "plaintext formats". JSON is an improvement because it is more structured, even more efficient, than those predecessors. JSON may not look efficient, but it compresses extremely well and can be quite efficient in gzip and Brotli streams.

I feel like "JSON over HTTP" is a subtle improvement over "custom text formats over telnet", even if it doesn't sound like "binary protocol efficiency" at first glance. Especially as HTTP/3 pushes HTTP more efficient and more "binary", and arguably "more fundamental/basic" with HTTP/3 even taking over more roles in the TCP/UDP layer of the internet stack. (Telnet would never try to replace TCP.) HTTP isn't the worst bootstrap layer the internet could use to build new protocols and apps on top of. Sure, it would be neat to see more variety and experiments outside of the HTTP stack, too, but HTTP is too useful at this point not to build a bunch of things on top of it instead of as their own from-scratch protocol.

A lot of the textual nature of older IETF protocols, including the CR LF line endigns, can be probably traced to how easy it was to bang out a bad implementation full of subtle problems that could be debugged by sitting an undergrad student at a teletype instead of spending time on having some binary serializer (that telecom companies definitely had money for)

Yeah, a fair bit of email protocol reeks of "is this tolerant of `telnet mailserver 25` and whatever garbage that might produce".

A lot of old RFCs explicitly mention running on top of TELNET.

Additionally, as much people like to harp about "telcos focusing on connection-oriented protocols while we ran loops around them with packets", the reality is that NCP and later TCP pretty much focused on emulating serial lines around, and one of the earliest ways to access ARPAnet outside of machines directly on it was through calling into a TIP which set up bidirectional stream from your modem to a port on some host.