What search engine app does the Django project uses itself in their website?
The search form in https://docs.djangoproject.com/en/1.11/
Is that search engine good for blogs? Or the one used by Zinnia (what app is that?) is better?
DjangoProject.com uses Elastic Search:
https://github.com/django/djangoproject.com#documentation-search
Elastic Search is a full-featured, modern search engine, and what you can do with it is far beyond the scope of a Stack Overflow answer. You can find out more about it here: