Both propose browser mining. But that's about it.
There's some big differences, Nimiq has been developed for 2 years now, is just an token and also they had an ICO.

This one will have smart contracts, anonymity and really interesting mining concept, just to point a few. Also, the team has gotten to this point on their own money, no ICO done.
I think these kind of projects will start the next phase, after ICO madness. Good old open source implementation, organic growth, clear and intuitive enough platform/interface to be used by my grandpa.