One technology that has been getting good reviews and lots of attention laterly is Ruby On Rails (RoR). It is a Rapid Internet Application Development framework that is easy to use and really fast to write applications in.
One of the drawbacks is that it requires the Ruby programmng language, which although powerful, is less widespread than other languages, and hence not available at most web hosts.
Now there is CakePHP, which is supposed to be Ruby On Rails but for PHP, the most widely deployed web development language. CakePHP follows the Model-View-Controller architecture, and provides basic CRUD (Create, Read, Update, Delete) operations. Of course, it is fully object oriented, just like RoR is.
No explicit license is stated on the web site, but according to the project page on Freshmeat, it is Public Domain (MIT style license).
The project is fairly new, as it has been added to Freshmeat only in April 2005. The project was started by Michal Tatarynowicz from Poland.