I did some due diligence on static site generators at the beginning of the year, first writing down my desired attributes:

* Actively maintained

* Supports Markdown

* Written in Python

* Flexible templating system

* Supports RSS/Atom feeds

* Supports syntax highlighting

* Track history (been around for at least a year)

The above list seemed like a good place to start, and after going through all the various candidates, the one that met all my criteria was Pelican. I liked the project and its author enough to eventually join the team as a committer. Check it out at: http://getpelican.com/

Cactus looks interesting, but I prefer having a wider range of deployment targets (instead of just S3). I also prefer the Jinja templates that Pelican uses instead of Cactus' Django templates. Just my two cents, of course. All of the various static site generators bring something interesting to the table — the more the merrier!