This is an important thing. I am pulling together a group now for a series of campaigns and the lack of a share compendium of our homebrew / hand imported third party material is making it hard to recommend going with Roll20. I understand that Roll20 is 1) afraid of creating a sort of pirate sharing space of official material that is shared without permisions and 2) secretly afraid of losing sales of material that is available on Roll20 that people own in another form, and would copy in by hand to keep around. Despite these fears, this type of feature is absolutely essential for anyone thinking of building a series of campaigns here. We know the tech is there for compediums, just sort out the permissions please. Otherwise, people either have to use one of the third party importers into Roll20 (lame, probably against the Terms of Service, and not what Roll20 should want). or leave the platform (also not what Roll20 wants). You clearly have the tech to allow this feature, and just need to change the permissions around it. I can already create a compendium if my goal is to sell it as a module on Roll20, so you just need to make it possible to create one to use yourself.