The source code which drives the current LibreOffice extensions and templates website is available for checkout and development on Github.com in a public repository (https://github.com/tdf/extensions.libreoffice.org). It’s easy to checkout the code from there and run a test site or development site yourself. There is nothing hidden. It’s a Plone site with some add-ons including a policy package and a theming package. You need only to run the usual buildout.