Aren't they doing some kind of goofy open source/proprietary differentiation, just like FoundationDB was doing? It looks like "the full copy of HyperDex Warp" (whatever that means) is what people are expected to pay for.
Hyperdex is the result of their ongoing research at Cornell University. They have a commercial spinoff which sells Hyperdex Warp which adds full ACID transactions on hyperdex. So if you don't need full acid transactions, you can use the OSS version, if you want the extra services you have to pay.
It's the same with all software, really: to be able to do a large scale project you have to have funding from somewhere, as you need developers full time working on it to fix/write the stuff no-one wants to fix/write. Some OSS projects get this funding indirectly by sponsored developers who work at company X and write OSS code all day for the project (this is what Linux uses). Other projects are funded by VC money, licenses, support contracts or ads. It's not common a large scale OSS project is successful and stays successful without any funding from the outside.
Thus, if a piece of software gets its funding by selling licenses (like with Hyperdex Warp), it's the same as with a company getting funding by sponsoring: if the cashflow stops, the show ends. In the case of OSS you can grab the sourcecode at least, but in the end, to successfully maintain that it takes a lot of effort most of the time, as the projects are often large, complex and the internals unknown to the user.
