blohg is a Mercurial (or alternatively Git) based blogging engine written in Python, built on the top of the Flask micro-framework and some of its extensions. All the content of the blogs are stored inside repositories, and the repository history is used to build the posts and pages.
Everybody knows that we have a large number of blogging engines lying around the blogosphere, but there are not a many choices for programmers, who are used to working daily with source-code editors and version control systems and may be more productive when blogging using these tools, instead of the fancy WYSIWYG editors and administration interfaces.
Actually this isn't the first project trying to implement a VCS-based blogging engine, but most of the existing projects aren't tied to a VCS and are just using text files that can be versioned with a VCS, without taking full advantage of the VCS's revision history.
This project uses Mercurial (or even Git) as the VCS, reStructuredText as the markup language and Jinja2 as the template engine. All of these are pretty popular within the Python ecosystem and easy to use.