Under the hood, Nest makes use of Express, but also, provides compatibility with a wide range of other libraries, like e.g. Fastify, allowing for easy use of the myriad third-party plugins which are available.
Nest aims to provide an application architecture out of the box which allows for effortless creation of highly testable, scalable, loosely coupled and easily maintainable applications.
Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support by the amazing backers. If you’d like to join them, please read more here.