Every skin's code is completely open, and can be tweaked, modified or even completely rewritten using any text editing software. All of these things are made possible by Rainmeter's unique code language, which allows a skin to access functions and resources built into the Rainmeter application. Skins can interact with other skins and applications using special commands, called bangs, and they can be customized by changing short lines of text, called variables. However, all skins are made from the same building blocks: measures, which gather information from your computer, a website, a text file, or some other source and meters, which create visual elements in the skin's window, such as frames, borders, backgrounds, images, text, charts, or buttons. Every skin works differently, depending on the choices of that skin's individual author. Some skins even come bundled in large 'suites' and include their own tools for customizing their form and appearance, within or alongside Rainmeter's basic user interface. Others are more complex, like miniature applications themselves. Some skins are very simple, single-purpose tools, like Windows desktop gadgets, or 'widgets' on an Android device. Rainmeter can run any number of skins at one time, even from different sources.Ī skin can be many things. Each skin is a separate window, and can be moved around on the desktop by clicking and dragging.