So, Tumblr went real-time last week. Cool.

Now the blogging platform’s 2.5 million users can send up-to-the-second alerts to any service that supports the popular PubSubHubbub publish/subscribe protocol for near real time notifications.

The added support for PubSubHubbub (can you say that ten times fast?) proves two things:

  1. Tumblr’s got its dukes up. Heavy competitors like Blogger and Posterous (which both added support for PubSubHubbub earlier this year) look like they’re in for a worthy fight.
  2. Real-time is still headlining our Web experience.

Twitter has certainly captured the real-time Web arena's attention in a big way, but PubSubHubbub-enabled feeds are also beginning to make their mark.  Clients utilizing them receive pings immediately after a post has been published. This is golden compared to standard RSS feeds which, as you probably know, poll at defined intervals

PubSubHubbub -- An Overview

FriendFeed, FeeBurner, Netvibes, LiveJournal and Lazyfeed are just a few more examples of the growing PubSubHubbub fan base, so if you're not in the know already, you might want to get familiar