Just my opinion, but the two most useful pieces of information that helped me understand what this does and visualize where it fits were

1) https://deepstream.io/tutorials/concepts/what-is-deepstream/ > "What is it for" section

2) and your comment that it's an alternative to firebase, socket.io, meteor.

Perhaps you can think of using these two pieces of information as the front-page blurb rather than make it abstract.