Hey all,
Hot on the heels of the switch to Eventlet, I've brought back CherryPy's WSGI server as the default HTTP engine for the server bundled with aspen. This is a high-quality prethreaded server, so it's a good choice for many applications. It's nice because it doesn't require any external dependencies, and it lets you use any libraries you want in your simplates without having to be overly concerned about or even aware of concurrency issues. If your application does require cooperative scheduling, you can easily use the eventlet HTTP server by installing eventlet, and starting aspen with --engine=eventlet or setting engine=eventlet in the [aspen.cli] section of aspen.conf.
chad