The isomorphic libraries and frameworks.
Isomorphic from the Greek "isos" for "equal" and "morph" for "shape". Isomorphism describes that if you look at the same entity in two different contexts, you should get the same thing. Here the contexts are server and client. Although the term has been mostly used in mathematics until now, it's an apt term to describe a web programing pattern where the code is shared by the front-end and back-end.
There are various isomorphic frameworks and libraries. Here is a list of the most popular isomorphic frameworks and libraries.
Faster to render HTML content, directly in the browser. Better overall user experience.
Free progressive enhancements.