The RedHttp project is no longer maintained. See Carter for a similar low-ceremony experience.
Handlebars renderer extension for RedHttpServer using Handlebars.Net
After installing and referencing this library, the Red.Response has the extension method RenderTemplate(filePath, renderParams, ..)
RenderTemplate(filePath, renderParams, ..) takes the path of a Handlebars template file and sends the html, rendered using the render parameter object, as response.