Four short links: 9 July 2009

1. Ten Rules That Govern Groups -- valuable lessons for all who would create or use social software, each backed up with pointers to the social science study about that lesson. Groups breed competition: While co-operation within group members is generally not so much of a problem, co-operation between groups can be hellish. People may be individually co-operative, but once put in a 'them-and-us' situation, rapidly become remarkably adversarial. (via Mind Hacks)
2. Yahoo! TrafficServer Proposal -- Yahoo! want to open source their TrafficServer product, an HTTP/1.1 caching proxy server. Alpha geeks who worked with it are excited at the prospect. It has a plugin architecture that means it can cache NNTP, RTSP, and other non-HTTP protocols.
3. App Engine Conclusions -- I've reluctantly concluded that I don't like it. I want to like it, since it's a great poster child for Python. And there are some bright spots, like the dirt-simple integration with google accounts. But it's so very very primitive in so many ways. Not just the missing features, or the "you can use any web framework you like, as long as it's django" attitude, but primarily a lot of the existing API is just so very primitive.
4. Microsoft Hohm -- Sign up with Hohm and we'll provide you with a home energy report and energy-saving recommendations tailored to your home. Wesabe for power at the moment, with interesting possibilities ahead should Microsoft partner with smartmetering utility companies the way Google Powermeter does. This is notable because this is a web app launched by Microsoft, with no connection to Windows or other Microsoft properties beyond requiring a "Live ID" to login. For commentary, see Microsoft Hohm Gets Green Light for Launch and PC Mag. (via Freaklabs)

Announcing: Spike Night at Velocity

Guest blogger Scott Ruthfield is a Program Committee member of the O'Reilly Velocity: Web Performance & Operations Conference.