Django is Python's killer app, and DRF is Django's killer app.

I think versatility and the absolutely easy on-ramp are Python's killer app. The 'absolute noob' can start writing simple python code after 5min of introduction (you can start using it like BASIC), while the 'senior dev' can still write python after years and isn't turned off or overly constrained by the language. (Yes, of course, warts exists, no language is perfect)

And regarding Django being the killer app: There are other people for which numpy/scipy is Python's killer app, for example.

agreed - maybe it will be integrated into django someday like south was

I believe that both the Django Core team and Tom Christie (DRF author) have stated that they have no desire to see DRF brought into Django, as that would tie DRF updates to Django updates, which would potentially slow down DRF releases.

makes sense.

The new Django Migrations from 1.7 are heavily influenced by the south project, but are slightly different.

was south integrated? the docs say it hasn't http://south.readthedocs.io/en/latest/about.html#a-brief-his... but maybe it's outdated?

The main developer of south was responsible for bringing schema migrations to Django's core... don't know how similar it was to south's codebase, though: https://www.djangoproject.com/weblog/2013/mar/22/kickstartin...

Its pretty similar from developer perspective.

That doc is dated 2010. Further proof docs lie ;)

But as other people said, no idea if it was copied and pasted into the django codebase or rewritten from scratch.. but everything South did, I believe Django now does.

Rewritten by the author of South. Basically, all the good ideas of South with some of the problems fixed.