Sorry, perhaps I haven't described the problem well first time. All your answers are interesting, but most of them are almost full-featured web browsers, my task is much simpler.
I'm planning to write a GUI application using one of the available on linux GUI frameworks (I haven't yet chosen one). I shall use html in my application to render into one of my application frames text with some attributes — different fonts etc, which are stored in CSS.
The html shall be generated by my application, so the only task is to render a html / CSS string. Is there any widget which can do only that render and nothing more — no history, no bookmarks, no URL-loading etc? If there isn't I shall use one of those you advised — it's ok — but I'm just interested if there is just an html-renderer without any extra features.