I really hate it when someone answers a question with "your question doesn't matter. What you should be asking is [whatever I think you should be asking] "

I assume the person asking the question has good reasons for asking it. If I can I answer. If not, I don't.

Coming to the question proper, there are often good reasons to ask if other people use / don't use a particular technology.

To answer, I use a custom variant of scheme to write machine- learning systems on a cluster of cots machines. It compiles down to optimized C, but I write in scheme.

A big part of it is the fact that Scheme is simple and Common Lisp is not. This is a "soft" feature, but I think it's important. I want to try out Scheme and see if it feels better.

I ask because I'd like to get a perspective on the tools that are available from people who actually make things with them. The programming language I use might be a "secret weapon" in some situations, but most of the people it would give me an advantage over wouldn't even understand why it's an advantage.

The problem I had with Scheme was that it doesn't stay simple. The core is certainly more elegant than Common Lisp's, but all the cruft has a nasty way of sneaking back in through SRFIs and big hairy macros.

I think continuations is an advantage if you don't use ajax. When you use Ajax, continuations in a web framework aren't needed. This has been my experience with the last two web applications I've written using CL and UCW.