Letterpond is a general-purpose modular PHP framework for the rapid development of web services. It's intended to allow the easy separation of projects into several logical segments, while still keeping the development process as easy and streamlined as possible.
Letterpond is currently in a pre-apha state, and as such has no formally packaged releases. If you're a brave soul, you can check out the latest code from the git repository (git://letterpond.git.sourceforge.net/gitroot/letterpond/letterpond), or grab a tarball of the current HEAD. Any suggestions, criticisms, bug reports, patches or other feedback are more than welcome.
Letterpond is licensed under version 2.1 of the GNU Lesser General Public License. In a nutshell, this means you can do more or less what you want with it - even sell it or link to it from your own proprietry projects - but if you modify Letterpond itself you must provide the source code for those changes.