Never encountered it before, but it looks cool.

I think they are trying to solve a related problem. "We can consolidate the work by making a generic log that has networking and syncing built-in. This can be used by developers to make automatically-decentralized apps without writing a single line of networking code."

At a first glance, I would say that Gossiplog is a bit more low level, targeting developers of databases and queues, to save them from re-building a log every time. But then there are elements of sharing the log between components. Worth a deeper look, but seems a bit lower level abstraction.