Zepto. js is a lightweight JavaScript library that is compatible with jQuery. It aims to provide a familiar and versatile API, similar to jQuery, while being only 5-10k in size.

With Zepto, you can easily develop web applications in modern browsers. Zepto offers a range of modules, including Core, Ajax, Event, Form, and IE, to support different functionalities in your projects. Zepto is open source software and is released under the MIT license, making it suitable for both developers and businesses.

You can download Zepto from their website or through alternative methods like npm or GitHub. Zepto is supported by most modern browsers and browser-like environments, providing a leaner alternative to jQuery for the mobile web. It is also a good choice for browser extensions and developing HTML-based views within native app frameworks.

If you are looking to build custom versions of Zepto, you can utilize their build system to select specific modules and optimize your code. Overall, Zepto is a reliable and efficient JavaScript library for developing web applications with ease