Jabber technologies have always been optimized for sending many small pieces of structured data, which we call XML stanzas. As a result we've struggled with ways to send binary data -- even small bits of binary. Out of that need emerged XEP-0231, which I recently renamed "bits of binary" (a.k.a. "BoB") because I like catchy spec titles (hey, it's one of the things that keep me going). Folks like Ralph Meijer have had vague worries about the approach we'd taken in that spec, but we needed it for anti-spam CAPTCHA forms so we kind of brushed those aside because we need to fight spam, right?
Then over the last few weeks Pavel Šimerda raised some further concerns and, more productively, suggested solutions. So Pavel and I have been collaborating on revisions in a longish email thread, in a groupchat the other day, and in follow-up email thread. Pavel has been a pleasure to work with and it was fun to make such significant progress in such a short period of time.
Best of all, I think "BoB" is one of those building block technologies that we'll be able to use for features like emoticons, thumbnails for file transfer, in-line images in messages and whiteboarding sessions, and yes those CAPTCHA forms for joining chatrooms or initiating presence subscriptions.
So here's to BoB! :-)