Disqus comments and article submission
Comments and article submission/modification
Some time ago, I developed a login/commentary system for this blog. There was a little work to do (this blog is developed with django) but it worked, so it was fine for me. With time, I decided that it was too much work for an user to post a comment : you need to register, give your email adress, then post your comment, it is too much to do for just a simple comment. That's why I decided to use an external service : disqus.
So if you have a question, or information, or want to express yourself, feel free to do it in the comment section !
Also, disqus uses django, they made an interesting post about how they scale to billion of requests : https://blog.disqus.com/scaling-django-to-8-billion-page-views
Edit: I find a little interesting detail. Disqus seems to auto dectect the main color of you site, and use it as its color (look disqus "theme" color is orange at the bottom of this article), so that the visual integration is smooth.
I also developed a system that let you write a new article that you wanted to be on vulgairedev. It worked too, but there was somme issues: I didn't let the possibility to upload files (for security reasons), which includes pictures, and it was impossible to save your article to modify it and send it later. Instead of developing thoses functionalities, wich takes time, I chose to use something that many devs use, wich support markdown: github. Now you can modify or add an article on github, and make a pull request. You will just have to wait for the integration.
As I said github supports markdown, so you can directly see a preview on it, you can add picture in the markdown, you can even add latex mathematical formulas. It is not supported (yet ?) by github, but it is on vulgairedev.