Moka is a completely open source icon suite, and it is available to freely download for the Linux desktop.
Moka was created with simplicity in mind. With the use simple geometry & bright colours. Each Moka icon has been designed and optimized at every size to achieve the a pixel-perfect look for your desktop.
Also, one of the most comprehensive icon sets available, Moka provides thousands of icons for many applications. So no matter which Linux desktop you are using, Moka has you covered.
Faba is was designed with simplicity and compliance to icon standards in mind. Its purpose is to serve as a base icon theme to other themes (such as Moka). As such, Faba is only comprised of minimal set of icons for the system, select apps, folders, mimetypes, toolbars, etc.
To extend Faba, there is also a monochrome icon theme for panelled desktop environments.