Ktor is described as 'Framework for building asynchronous servers and clients in connected systems using the powerful Kotlin programming language. Ktor consists of two parts: the server engine and a flexible asynchronous HTTP client' and is an app in the development category. There are more than 10 alternatives to Ktor for a variety of platforms, including Mac, Windows, Linux, Android and Self-Hosted apps. The best Ktor alternative is Spring, which is both free and Open Source. Other great apps like Ktor are Jmix, ActiveJ, Dropwizard and Play!.