Finally, I've released the software I use to make this blog. It is a simple static site generator written in Python.
You can download it here https://github.com/rasmaxim/static-blog-generator.
Initially, I used wheezy.templates as the templating engine. But its syntax was too uncomfortable to use. "If I want someone else to use this software, I need to change the templating engine" —, I had thought. So I changed it to Jinja2.
Also, I removed a lot of useless classes and abstractions. As a result, my script has only ~400 lines of Python code and only one class.