A list of Open Source External Libraries used by Cosmo:

Library	Description	Tutorial	Cosmo Usage
jcr-server	WebDAV library		Cosmo Extends the JCR Webdav to support CalDav.
Dao	Abstract API for storage access, the underlying storage being the filesystem, RDBS or any other form
Derby	Small footprint RDBMS in java	Derby FAQ	Persistence storage area - CosmoDerby describes Derby in Cosmo.
Log4J	Logging API	Short Manual	Used for logging different cosmo events, includes debug and informational log messages.
Spring	Provides configuration management using Dependency Injection, also provides JDBC abstraction layers, Transcation support and more	Spring Intro
acegisecurity	Authentication, Authorization, Access Control system	Reference Guide
Maven	Build System with enhanced features like automatic site creation, javadoc creation, building the project, etc	What is Maven?	Used to build Cosmo, also helpful for generating the javadocs (maven javadoc)
Tomcat	Servlet Container		Part of the OSAF bundle, serves the web application
Struts	Framework for rapid web development	Struts Action Example	struts-config.xml provides the mapping between the different URL's and the action (Business objects)