Google has released the Google Noto Font, the only font to feature all 110,000 Unicode characters and cover 800 languages. The intention is get rid of the “⯐⯐⯐⯐” sometimes encountered while browsing the Web or viewing some types of PDFs. Noto is a 480Mb download. You may not want to install all the language versions of the font, as that may well slow down the loading times of behemoth software such as Photoshop.
Since the font is Open Source, the vast variety of shapes from around the world can also serve as a ‘design-mine’ for graphic designers.