Basically, you don't want to combine the two in the sense that you write your own components and application code with both. But you could combine the two in the sense that you write your application with Aurelia and then use Polymer elements inside your Aurelia views. Since Polymer's best feature is its component library, it makes a lot of sense to combine them in that way. In fact, community members have been doing that for a while and we even have a plugin and documentation for that use case. You can read more here: aurelia.io/docs.html