11ty is "a simple static style generator" (SSG). It is targeted at building static "sites", not web "apps".

11ty competes with:

• Gatsby (React)
• Hugo (Go)
• Jekyll (Ruby)
• Next (React)
• Nuxt (Vue)
• Sapper (Svelte)
• and more

What distinguishes 11ty from other popular SSGs is that it is more inclusive. Content can be contributed from people with a variety of skill sets. Most SSGs support Markdown content. But there are typically features that can only be used by contributors that know a particular web framework (such as React or Vue) or programming language (such as Ruby or Go).

11ty also has features that can only be used by programmers, but they only need to know basic JavaScript. For contributors that are programmers, it's more likely they will know JavaScript than other programming languages.

11ty supports a wide variety of templating languages /blog/eleventy/ssgs/ and use of these can be mixed within the same site. All the supported templating languages require less effort to learn than learning a new web framework or programming language. This increases the pool of potential contributors to a site.