Yes rebol can be used to script web pages, like jsp, asp.
And that, is primarily where it is used, if you ask me.
Web projects may be the most visible ones, such as Cheyenne server and QTask, but they are far from the only ones.
There really isn't much point to rebol for generic application development.
Actually that is the whole point of REBOL and I make my money today because I do generic application development in REBOL.
The generic design of REBOL allows it to work on any task, except for high performance calculations, where you would use extensions written in C or other high performance language.
It's also not likely that you would write an operating system in REBOL, but REBOL 3's modular design allows it to sit in more places, such as directly on top of a kernel, which is to become the Wildman project at some time in the future.
What's odd about Rebol is a few years ago, it supported almost every platform available - and that wasn't really important because everyone was using Windows.
The problem was that Carl Sassenrath had set up a development model that dictated that every piece of code, documentation and also maintenance task had to be done and checked by himself. Hence, development slowed to a crawl. The REBOL 3 development model solved this 3 years ago by making the kernel smaller and peripheral code (the hostkit, i.e. how the kernel talks with the OS) was open sourced.
Now, we have this real split in the marketplace, where some are using Android, some using iOS, some using Blackberry, some using WinMo - on their Smartphones, and soon, on their tablets....
and yet now Rebol punks out and doesn't support any of those devices.
Time limitations and also focus on getting the REBOL 3 core completed. It's very complex and a huge amount of work. But the REBOL 3 hostkit already runs on different OSes now, as you can see, and the role of porting is now in the hands of 3rd party developers, where it should occur.
Now I've been an it professional for a couple decades now, I know why it would be difficult to support a platform, when well...Apple is blocking you. Google maintains control over Android too, despite the impression of being so open.
But - that's the challenge in this world...unfortunately Rebol doesn't solve too many problems, and I love scripting languages, and I agree with a lot of Carl's rhetoric, I just don't believe he's found any great answers.
Even the bill for the old Rebol of being a dialecting language was a bit of a joke, because he didn't even understand people speak different languages (talking about spoken languages and their intersection with programming languages)....what's the point in creating dialects, and missing the big picture about differing languages all together.
The point of dialects is not to make something that just is different from the syntax of the language itself for fun. It's to allow a different type of express-ability to simplify what it is you want to do without specifically writing an API. Dialects is something that is not very important in other languages, thus they are either misunderstood or ignored.
Dialects allow greater express-ability and coupling dialects with 56 datatypes, you can express and parse meaningful data in a wholly different way than you would otherwise be able to, when using the standard syntax alone.
But I digress....that dialecting stuff isn't even mentioned a lot anymore, so we can move on from that.
Actually no. Dialecting is one of the big reasons to use REBOL and REBOL 3 extends this a great deal with improved parsing and more dialects.
Without dialects, half of REBOL's design philosophy goes out the window, most of my programs wouldn't work, so we can most certainly not move on from dialects. :-)