UPDATE: As of July 30, 2013, development of Ryouko has officially ended. As fun as it has been to work on Ryouko, I have concluded that its codebase is too messy and reimplements too much functionality that is already provided by PyQt4. Therefore, I've started work on a new browser, Nimbus. Nimbus isn't anywhere close to matching Ryouko in terms of features yet, but its codebase is cleaner and easier to work with, and it integrates with Qt more nicely. With time, it should eventually reach the point where Ryouko now is. And yes, Nimbus does work on Windows (or at least in Wine). The Nimbus project page can be found at https://github.com/foxhead128/nimbus.
Ryouko is a Web browser coded using Python 2/PyQt4. It was originally designed to run on Linux, but a Windows version is now available as well. Ryouko was coded purely for fun, and is currently missing a lot of features. Therefore, it is not meant to replace your default Web browser, nor is it intended for serious usage or people who need a stable, dependable, and fully-featured program. However, it should be okay for very basic Web browsing.
A known issue is that the ad-blocker may cause the browser to hang on complex sites/slow computers.
For source code and compilation instructions on Windows, see ryouko_lib/README.txt. For documentation and questions you may have, check out the new wiki at https://github.com/foxhead128/ryouko/wiki.