# About

Ondesked is a markup language which is used for developing GUI for desktop apps.

It's based on XML, and is similar to HTML; if you know HTML, you already know some of Ondesked.

Every Ondesked document should have an `app` element as the root element. Just like this:

```markup
<app>...</app>
```

You can think of it as equivalent to an `html` tag.

> Ondesked is designed to be strict, to prevent any unexpected behavior, and to keep codes consistent. So, every Ondesked document should start with `app` tag, otherwise it just won't work.