Download SharePoint Add-Ons:
All software downloads below (about 3-8 MB each) are free and fully functional.
Each contains: Setup Wizard with SharePoint "Farm Solution Packages" (WSP files),
all in English and German — as well as:
Documentation: integrated in SharePoint (upon solution deployment) under Site Settings / <Product>Zen Studio / Help Topics (English and partially German)
Instructions:
Extract the Setup Package on your SharePoint primary farm server (logged into Windows as a SharePoint Farm Administrator). From there, follow the Installation section in the accompanying readme.html document.