Bootstrap creator here.
tl;dr: First, thanks for the love everyone! Jacob and I love seeing people as excited about the future of Bootstrap as us. We're hopeful that this is just the beginning of it. And now, onto answering some of the questions/comments folks have brought up here thus far.
Jacob left over a month ago and my last day is next Friday (10/5). He's going to Obvious, and (announcing it here for the first time) I'm going to GitHub.
The timing has nothing to do with a disagreement about Bootstrap (seriously, none what so ever), and more to do with us both wanting a change in our own lives for what we do day-to-day. Twitter, the company and product, are both amazing and Jacob and I have worked there for 2.5 years. We're stoked for our next things and we both want to keep working on Bootstrap no matter what. We have an obligation to the community and know it could go much further. (Oh, and yes, I screwed up the date on the post. My bad, yo.)
Bootstrap was created by me at Twitter as a means to make better looking internal tools (I wrote about this on A List Apart awhile back: http://www.alistapart.com/articles/building-twitter-bootstra...). It started off as a simple HTML/CSS thing, then Jacob built plugins on top of it, and we open sourced it together. We made it at Twitter, so when we wanted to open source it, we went to Twitter to ensure it was good to go. Thus, it was named Twitter Bootstrap (originally, "Bootstrap, from Twitter" actually). Now, it's back to just "Bootstrap".
We don't really think of it as the next jQuery, Django, or Drupal. But you can't deny there is something to front-end frameworks like Bootstrap, and that's what we're excited about. HTML and CSS are the two easiest and most basic building blocks of websites. Everyone knows and uses them, and that's a big part of why Bootstrap has grown so much, and can continue to grow more.
No, we weren't "given time" to work on Bootstrap, but that's because it was a project I started on my own to help other engineers. Jacob came in to shape it into a proper open source project and then wrote all the JavaScript plugins (Fun fact: before the jQuery plugins, he wrote a MooTools library on top of it called Tit, which is a type of bird). Anyway, we weren't given time because it wasn't a company priority, naturally, and we're okay with that. We worked on it, at the office or at home, whenever we wanted and folks were generally okay with that as well.
The move to making Bootstrap its own project and organization is a joint one, between myself, Jacob, and Twitter's Open Source team (@cra). The transition will take time, but we need to grow Bootstrap beyond the two of us and Twitter, and into something more. There is really sooooo much potential for making better things on the Web, and we're hoping we can keep that up with the help of the community.
Anyway, we're both stoked to keep working on Bootstrap. It's a great project that can be so much better, and that's pretty damned awesome to us. Twitter has been amazing for both of us and will continue to down the road. We wish nothing but the best for everyone we've worked with.
<3