This is pretty close to the absolute bare minimum of what you would need to install a theme to publish WordPress content. I created it as a learning exercise to show how basic WordPress theme development can be.
This theme can display single posts and pages, a homepage with posts, search results, a 404 page, and a sidebar and footer from a single index.php file.
It does not have internationalization, custom post types, or other common features. Just the minimum code to get a theme off the ground.
It needs some clean-up to match WordPress standards, so I'll be doing that next. It also needs page-to-page navigation and a couple of other actual features (but again, bare minimum).
It has no CSS styles at all. Add some!
Explore the files for documentation about why each part is necessary. You can use this as a from-scratch (seriously, from scratch) starter theme, add your own CSS, add more template files, whatever you want. Hope it helps. I'll be publishing a full walkthrough tutorial in the coming weeks.