Now here’s an open-source project that knows how to look good. The banner at the top sets a bold color theme that the rest of the page uses and has a simple set of menus below with the important points for a software project. Subtle use of gradients gives it a professional look and the big screenshot (of an equally nice-looking UI) lets the graphics do the talking. All XHTML/CSS compliant (as is their product); the “made on a Mac” logo at the bottom shouldn’t come as a big surprise. The concise sidebar is on each page, giving a consistent UI for the main pages of the site.
It’s also a nice site for a web project − very clean, with nice screenshots, captions and use of bullet lists to keep things readable. All in all, the best SourceForge project page I’ve ever seen. (RoundCube Home Page)