So a double post for something some of you may find useful/awesome.
AwesomiumIt's an HTML5 based thing which integrates with native code. Incredibly simple to set up and use; great for UI.
It's built on top of Chromium, so it is literally a web browser for within your code, complete with everything that comes with that: javascript, CSS, HTML, WebGL, flash. Like any other web browser, it can access local stuff or from the internet (a group member was using it to watch youtube videos from within the game earlier today). It's awesome. It can either be tied directly to a window, allowing you to ignore handling its stuff almost entirely, or can be used to create a texture for other stuff in the application. Or in other words, you can not only use it for UIs, but you can also use it for a web browser within your game, be it a HUD element or an actual browser-in-a-texture which could then be placed in a 3D world. It allows for injection of mouse and keyboard events either from window messages and/or from code-specified stuff, giving a huge flexibility to how you use it. When it needs to update the image, it gives you a char array with the part of the texture to update, and specifies what rectangle needs to be updated with it.
Additionally, since you could in theory use WebGL with it, I'm pretty sure you could actually create something akin to a nested 3D world through a recursive implementation without any actual work (which would be hilarious and kinda awesome).