When comparing Harp vs Assemble, the Slant community recommends Assemble for most people. In the question“What are the best static site generators?” Assemble is ranked 14th while Harp is ranked 28th.
Ranked in these QuestionsQuestion Ranking
Pro Compiles assets on request
Rather than regenerate the whole site when a file changes, Harp only reloads what is necessary, keeping the compile time fast.
Pro Supports popular languages
Harp supports a large variety of languages, including Jade, CoffeeScript, Stylus and Sass. See the full list here.
Pro No dependencies on Ruby, Python... just JavaSctipt!
Pro Built on node.js
Pro Powered by a popular template engine Handlebars
Handlebars is the default template engine for Assemble, but you can add any template any you want.
Pro Highly customizable
Pro Markdown support
Pro Highly extensible
Assemble can be extended with plugins/middleware, helpers and mixins.
Pro Nested layout support
Assemble makes it easy to work with layouts. Layouts are used to "wrap" pages with common page elements, such as a header, footer etc. You can even nest layouts!
Pro Use mainstream build tools Grunt or Gulp
Con Limited extensibility
There are no plugins available to extend the functionality or language support of Harp.
Con Documentation can be hard to navigate
Especially for someone new to Assemble, it can be difficult to find what you're looking for in the documentation.