Its old but I stumbled onto this just today. Zed Shaw (the creator of that ol’ faithful Ruby server mongrel) is a fan of the Apache Passenger (modrails) guys

I also met the Phusion Passenger guys and holy fucking crap are they on to something. If anyone is going to actually take on Mongrel in the hosting area it’s Passenger. The developers are super cool nice guys (unlike me) and even DHH likes their stuff. He really never liked anything I built, so hopefully those guys get more support. About the only thing keeping them from taking over is that they use forking so a few libraries that keep resources open will have serious problems. They’ll probably have to think up some kind of thing for that soon, but I think most Rails deployments could get pretty far with Passenger.

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Honestly though, it shouldn’t be that hard to beat Mongrel since Mongrel is crippled by Ruby. What the Phusion guys are pulling off is just using Apache to do the heavy lifting and then let their module do the work to stream out to Rails. It’s not a new idea, they’re just doing a great job marketing it and educating people while keeping things simple. The kicker is that they also have support for Rack and WSGI. Now that’s fucking sexy.

Now, thats one hell of an endorsement