To add some fluff to this: At one point twitter seemed to want to be a relatively general protocol, where users could build their own UI, use 3rd party apps an

To add some fluff to this: At one point twitter seemed to want to be a relatively general protocol, where users could build their own UI, use 3rd party apps and maybe even interoperate or extend with other social networks & such. Pg/yc even wrote about it, inviting startups to start writing apps for this exciting new protocol. The early app ecosystem was pretty slimy, with a lot of spam-ish clients for promoting snake oil. More importantly, it became clear that controlling the UI means control over users: the data, rights, often and the ability to decide what goes into people's feed. That's where the (financial) value is, and they're not going to give that up. TBL's ideas were naive perhaps, but he did have his thumb in the right place. Something like semantic web was necessary, in order to avoid the centralisation that did end up happening. RSS, via podcasting did catch on. Today it's one of the only "free" media forms. There's no company moderating podcasts like twitter, FB, youtube, etc.