Our paper “Experience Report: Scheme in Commercial Web Application Development” is online. As the title suggests, it describes our experiences over the past year developing a number of web-based applications in PLT Scheme. If we'd chosen a language like Java or Ruby we could have used a large number of libraries developed for web apps, whereas PLT Scheme has relatively few libraries in this area, and they haven't been tested under high load. So we were gambling that Scheme would make us so productive we could develop our own libraries and the applications we were contracted to produce in the same time it would take to develop just the applications in another language. It was a gamble that paid off. You'll have to read the paper for all the details, but suffice to say we delivered the applications on time (and more are in development) and our libraries already compare well against big names like Ruby on Rails and J2EE.
Update: This is more or less the same post as on Untyping