Web developers: Watch out for Meteor!

 Meteor, a new real-time JavaScript framework targeting web app developers, is causing quite a stir on Twitter and Hacker News.
The product will let developers keep working in “pure” JavaScript and use the same APIs on client and server devices, according to Meteor’s web site. The Meteor platform API works everywhere, but development happens on the local laptop with Meteor handling the data updates and synchronization to the server.
What seemed to wow developers was Meteor’s claim to perform “hot code pushes” which update the app while users are connected to it — without disrupting them. According to the web site: “when you push a new version, the code is seamlessly injected into each browser frame in which the app is open.”
That’s a big claim that some commenters want to hear more about. One Hacker News reader wrote: “I dread the tests that would be necessary to make sure that hot updates won’t break anything.”
The software — which the company says is open source — is still in early stages (preview version 0.3.2 to be exact.) Meteor’s FAQ:

Meteor is still under rapid development. Expect major API changes in each release. Everything that we release has passed our automated tests and also a manual QA process, but we don’t have 1.0-level test coverage, so a bug or two may sometimes slip through.

Meteor people include Geoff Schmidt, who co-founded of Miro, an Internet TV platform, and founder of MixApp,  a realtime peer-to-peer music network. Two years ago he was  employee #9 at Asana, where he worked on the Luna application platform.

The discussion thread on Hacker News is lively with many commenters professing to be blown away at first glance, and then more than a little bit curious about the innards of the framework.
Wrote MichaelJansen:

My first impression of this: wow. If Meteor is all it appears to be, this is nothing short of revolutionary.
My second reaction: what happens when the magic ends? When I was new to Rails, I really loved how easy it was to get started with scaffolding, a nice DSL for specifying relations, nifty form helpers. However, the first time I veered a little off the golden path and wanted to do something a little more complicated (that was not supported by the form helpers at that time), I ran into a huge wall.

The San Francisco company has some pretty big fans.  Dustin Moskovitz, co-founder of Asana and Facebook blurbed the software on its Web site, as did Gary Tan, founder and designer of Posterous.
Given the hue and cry raised already, it looks like web developers will be kicking the tires on this one for some time.
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