I use both rails and django, and my impression is that although both frameworks were released at roughly the same time, they are both at very different points of the hype curve, with rails pulling out of the Trough of Disillusionment, and django rising to peak hype.
The thing about Django is Python, really. Ruby looks nice, but Python apps get the benefit of all the non-Django applications it's been put to: fast numerics through Numpy and Scipy, PIL, lxml, NLTK, Twisted, etc etc etc.
Of course, you could argue that Perl has even richer libraries, so...
This only matters if you need specific features from those libraries in your web app, there is no adequate library in another language and you can't use the python library without strong integration in the app.
Ruby's domain is primarily the web and web systems, and when it comes to that area, Ruby has an vibrant ecosystem with plenty of libraries and tools that don't have python counterparts. Ruby developers have also readily borrowed good ideas from Python. For vast majority of web development, these kinds of things matter more than the existence of something like scipy. Each language has its strengths and weaknesses with regard to the quality and quantity of tools directly related to web development.
Perhaps, but there's much more heterogeneity amongst PHP frameworks than Python or Ruby frameworks. For better or worse, Django and Rails are dominant in a way that Cake isn't. (Besides, all the cool kids moved to Kohana. We're not cool, as Dawdle is on this niche (read: dead) framework called Qcodo.)
Pylons has served us pretty well in so far as it seems a more modular approach vs. django. Pylons encourages you to tweak the framework itself as you see fit. In our case, we incorporate a bunch of custom framework code. I'm sure you could do this with django, but it just feels better with a minimal, modular framework vs. something that is on the monolithic side of things.
I think Rails has a special community that has a stronger concept of loyalty than the Django world. I wonder if a Django host might be a bit like Microsoft retail stores. The volume is there, but not the brand loyalty. (Note: I've never used either.)
It's not really true. Rails has it's controversies inside the community andmore attacks comming from outside.
Fortunatelly it's ecosystem grows fast and into the right direction. On posts like which language to learn -- Django or Rails -- one can realize Ruby community is well equipped with tutorials, screencasts, components, news, collaboration, hosting and deployment/tuning tools
Don't work at a startup, stopped writing web apps a little while ago and don't really miss it, but there's one framework that's constantly tempting me to jump back in: Seaside. Especially with the whole GLASS backend now.
There are a lot of companies which simply never talk about what they use internally; as such, it's really hard to get an accurate picture of what's really in use, because the only glimpses we get are the (fairly rare) places which choose to be open about what they're doing.
Based on that, and on interesting tidbits picked up from talking to people in the trenches and paying attention to little clues (interesting addresses showing up on mailing lists or IRC, peculiar code quirks, etc.), I suspect that if everybody laid their cards on the table the results would be surprising to people who think they know what the "mainstream" is using (and not just in the "lots of people using Rails/Django sense -- there are many more exotic things out there).
I'm sure you'll acknowledge that neither Rails nor Django is universially more used than PHP is. A better estimate is that PHP is about 100 times more widely used. The discrepancy between that and the results of this poll is so big I can't think of a word in the english language to describe it.
PHP is more widely used, yes, and that's obvious. But I didn't try to say otherwise.
What I'm objecting to is your apparent assumption that use of tools like Django or Rails necessarily sets one apart from "the mainstream", or even that there is such a thing and that it can be quantified.
Or, succinctly: there probably are a lot more people using not-PHP and not-Java than you think. Some are using hip, trendy new things like Django or Rails. Many are still using ancient, forgotten things like COBOL and IBM mainframes (some friends of mine deal with those types of folks on a daily basis). And there are a lot of places that aren't single-language shops, but have an amalgamation of code accreted over the years.
Which all adds up to the fact that you really can't make useful statements about "the mainstream"; all such statements tend, ultimately, to reflect hype machines rather than reality.
I used to use zend framework, moved onto kohana and I am looking now at doophp http://doophp.com/ - though I am really really (I promise) exploring an option to move to python/django. The problem is I have a mountain of legacy code which I don't feel like rewriting (it works!).
I wonder if the results would have been different if the title had led with the word Rails instead of Django. I certainly clicked the link because my lizard brain saw Django and before I knew it here I was.