Starting a new web app: catalyst, rails, or something else?

[napoleon_in_rags]

3. Well, when I used it I wasn't to afraid to hack it up.

To make it do what I wanted. Just a little reading made it possible. If you're looking for a really cogent, ready made AJAX built in system, Django probably isn't it. I read it has some add on functionality, through "tastypie" and "piston" but I haven't tried either of them.
http://stackoverflow.com/questions/6307992/best-way-to-integrate-django-with-an-ajax-library
But from the link above:

Basically, these libs help you create a fully working read-write API for your models, so you can perform create-read-update-delete operations from your javascript via HTTP. You don't need to define any views or serializers. Instead, you define resources, which is a decent abstraction, I think.

And it usually takes just a few lines of code, especially if your resources are tied to models.

If that sounds good to you, it might be worth looking into.

And I've never done any work with SVG, but as I recall it's a XML based vector graphics language. It wouldn't be hard to change headers from HTML to XML for any view, to create dynamic XML with Django, or really most frameworks.