It uses tagged template literals to render to the DOM, so on the server side it could fall back to vanilla string interpolation.
[1]: https://github.com/PolymerLabs/lit-html
[1] https://github.com/WebReflection/hyperHTML
EDIT: Yeah, looks like it's always worked that way. Maybe I was thinking of another lib.
It uses tagged template literals to render to the DOM, so on the server side it could fall back to vanilla string interpolation.
[1]: https://github.com/PolymerLabs/lit-html