Vapor

Vapor is one of the most popular frameworks, and it enjoys the support of a very active developer community. The support from a developer community means that there are a lot of releases, bug fixes, and help that can be expected. In fact, the development of Vapor has been closely following the Swift evolution development. With the launch of SwiftNIO from Apple, as well as Swift 4.1, the Vapor developer community quickly launched Vapor 3.0 (https://github.com/vapor/vapor/releases/tag/3.0.0), which adopts asynchronous and non-blocking event-driven networking stacks, alongside futures and promises throughout the framework, fully aligning with the latest technology in the Swift ecosystem.

Overall, Vapor caters for both beginner and veteran server-side Swift developers with simple and concise syntax, strong community support, and the appeal of pure Swift implementation.