Sinatra

Sinatra is a small domain-specific language for Ruby that makes it quick to build web applications. A basic app can be written in only a few lines of code.

You define routes that match web requests and return responses, such as HTML pages, JSON or plain text. Sinatra stays out of the way, so you choose your own database, templates and libraries. It runs on common Ruby web servers and is often used for prototypes, small services and internal tools.

• Simple route definitions for web requests
• Minimal setup and few required files
• Works with many Ruby web servers
• Compatible with popular template engines
• Open source project on GitHub

Ruby developers, teams building small internal tools and anyone who wants a lightweight alternative to a full framework. It is also a good way to learn how web routing works.

Sinatra is open source and free to use. It is a library, so your costs depend on hosting and the services you add. Larger applications may benefit from a full framework with more built-in structure, so consider the size of your project before you choose it.