Disqus enables people register using their cendential of Twitter, Facebook, Google or Disqus to comment blog posts. If you are using Pelican to generate a blog, using Disqus is really simple, just have to add some cinfiguration. All Pelican's standard themes are ready to use with Disqus, maybe all downloadable themes are ready to be used with Disqus.
The First step is create a Disqus account, just access their site and create a account. Now we need to register disqus to be used in a blog. Open the Disqus Engage then click in "Starting using Engage" you should be redirected to a form, fill this form using your blog info and click "Finish registration". Remmember the value you put in Disqus URL, we are going to use this value to configure our Pelican Blog. We are done in Disqus for now.
After you create your pelican blog, open your "pelicanconf.py" and add a new configuration line:
DISQUS_SITENAME = 'DISQUS_URL_VALUE'
We just that configuration to let visitors add their comments and start dicscussion inside a blog post, pelican engine takes care of all the rest for us during the site generation. Note that comments are not avaliable in developing server, you need to publish to see it.
Access your published blog to see the comments session like this: