is now live! – http://bit.ly/pwk4iwd
The Plugin_Developers_Guide-220.127.116.11.pdf is as the name suggests developers’ guide for plug-ins and pattern types (virtual applications).
The pdk-18.104.22.168.zip contains the actual IBM Workload Plug-in Development Kit, the contents are as follows:
-docs/PDKSampleUsersGuide.pdf: contains user guide for sample plugins and pattern type
-IBMWorkloadPluginDevKit_.zip: contains build libraries and build scripts to build plugins and pattern types
-pdk-samples_.zip: contains sample plugins and pattern type
-pdk-javadoc_.zip: contains Javadocs
If you ask, What is IBM Workload Deployer? see here http://www-01.ibm.com/software/webservers/workload-deployer/