<pclass="notice">July 27, 2012 — Leaflet 0.4 Released with <em>Lots</em> of Exciting Improvements! —<ahref="#">Read More in the Blog</a></p>
Leaflet is a modern open-source JavaScript library for mobile-friendly interactive maps. It is developed by [Vladimir Agafonkin][] of [CloudMade][] with a team of dedicated [contributors][]. Weighing just about <abbrtitle="That's 99 KB minified and 170 KB in the source form, with 8 KB of CSS (1.8 KB gzipped) and 10 KB of images">26 KB of gzipped JS code</abbr>, it still has all the [features][] most developers ever need for online maps, while providing a smooth, pleasant user experience.
It is built from the ground up to work efficiently on both desktop and mobile platforms like iOS and Android, taking advantage of HTML5 and CSS3 on modern browsers. The focus is on usability, performance, small size, [A-grade][] browser support and [a simple API][] with <abbrtitle="Simplicity and reasonable defaults so that the API doesn't get in your way, while not losing flexibility">convention over configuration</abbr>. The OOP-based [code of the library][] is designed to be modular, extensible and very easy to understand.
In this basic example, we create a map with <abbrtitle="Here we use the beautiful CloudMade tiles which require an API key (get one for free!), but Leaflet doesn't force you to — use whatever works for you, it's open source!">tiles of our choice</abbr>, add a marker and bind a popup with some text to it:
Learn more with the [quick start guide](examples/quick-start.html), check out [other tutorials](examples.html), or head straight to the [API documentation](reference.html).
The project is [hosted on GitHub][], waiting for your contributions --- just send your pull requests to [@mourner][] (Vladimir Agafonkin, Leaflet author and maintainer). Let’s make the best library for maps that can possibly exist!
You can also help the project a lot by reporting bugs on the [GitHub issues page][], showing your support for your favorite feature suggestions on [Leaflet UserVoice page][], tweeting to [@LeafletJS][] or joining the [Leaflet mailing list][].