In 2005, someone asked me in urgence to help him in building a webapplication to manage a conference. At that time, I was using Django (and I am still using it) but it was clear that setting up Django was not possible for technical and human reasons. That is why, I started Pluf to be able to code a webapp with ease but in PHP.
The framework is a Model, Template, View framework and you have a full control over the look and feel of the URLs (they can end with a slash, .html, .pluf, etc.).
The ORM allows you to easily create, update and delete things in your database but also query the database. Through views, you can easily create complex listings with multiple joins.
The template system is really nice, with automatic escaping of your variables to avoid script injection, a given template can extend another to have very simple templates most of the time and to not repeat yourself.
The performance is here, templates are compiled in PHP code, __autoload just loads what you need (or you can package the framework in a single .php file) and the execution stack is small between the request and the response. The core dispatch loop is the fastest of all the framework.
The code is actively maintained and improved with more than 2 years of production use.
If you update your models, a powerfull migration system allows you to upgrade/downgrade your database accordingly (peace of mind when doing deployments).
Read the doc to get started.
Oh, we have a new logo, nice work from Slavik.