Pow is a new zero-configuration server for Rack web applications by 37Signals. It makes development, especially on multiple applications, painless: it adds a new .dev domain, with individual apps symlinked from ~/.pow. Pow manages application instances automatically and integrates seamlessly with RVM.
Brent Simmons has lately been advocating for “baked” blogs. In a nutshell, a baked blog is one that produces static HTML files. These days, most popular blogging software stores content in a database and runs a bunch of code for every page request: pull the post out of the database, generate the page based on a template, and finally send the finished page to the browser. Under a normal, light traffic load, this works fine, but as soon as a post is linked by a very popular site, it buckles under the load. Best case, visitors get an error page. Worst case, your server crashes.