There are many modules that provide some sort of slideshow / rotator functionality.
This page summarizes the usage of all projects on drupal.org. For each week beginning on the given date the figures show the number of sites that reported they are using (any version of) the project. Detailed usage information for each release of a project is available by clicking the project name.
gibt überblick über aktuelle projekte im bereich social web/open web
Comparison of projects - The protocols of these projects are generally open and free. The software of the projects is generally free and open source.