As some readers of this blog may be aware of, Logilab has been developing its own framework since 2001. It evolved over the years trying to reach the main goal (managing and publishing data with style) and to incorporate the goods ideas seen in other Python frameworks Logilab developers had used. Now, companies other than Logilab have started providing services for this framework and it is stable enough for the core team to be confident in recommending it to third parties willing to build on it without suffering from the tasmanian devil syndrom.
CubicWeb version 3.0 was released on the last day of 2008. That's 7 years of research and development and (at least) three rewrites that were needed to get this in shape. Enjoy it at http://www.cubicweb.org/ !