Frappe is a full stack, batteries-included, web framework written in Python and Javascript.

Oatpp is described as 'Create fast web services with C++ using Oat++. It's a light, zero-dependency, no-installation web-framework' and is a Web Framework in the development category. There are four alternatives to Oatpp for Linux, Mac and Windows. The best Oatpp alternative is Frappe Framework, which is both free and Open Source. Other great apps like Oatpp are Crow framework, Cutelyst and Silicon web framework.
Frappe is a full stack, batteries-included, web framework written in Python and Javascript.

Crow is very fast and easy to use C++ micro web framework inspired by Flask Framework .
Silicon lets you write fast and robust web APIs with C++. It's a high throughput, low latency C++ Web Api development framework focused on ease of use and performance.