Internationalization (i18n) open source libraries and APIs
Localizing Android Apps
            Truly great applications use the right text, dates, numbers, currencies, and graphics for users and their locations. Android has great i18n support.
          
        
        
        
      Phone number library
            Google's library powers Android and more. Optimized for smart phones, Android's framework has included the Java version since 4.0.
          
        
        
        
      Address Input Widget for Android
            Support for validating user-entered addresses.
          
        
        
        
      International Components for Unicode (ICU)
            These mature, open source, public C/C++ and Java libraries are widely used, supporting Unicode and globalization.
          
        
        
        
      Chrome Web Store App i18n
            Tips and steps to follow when you internationalize and localize an app for the Chrome Web Store.
          
        
        
        
      Resources for multi-regional and multilingual websites
            Webmaster resources help you manage multiple regional and language versions of your website.
          
        
        
        
      Google Fonts
            With robust multi-lingual web font support, Google Fonts are quick and easy for anyone to use, including professional web designers and developers.
          
        
        
        
      Noto font
            Fonts for all Unicode characters across all languages.
          
        
        
        
      Google Web Toolkit (GWT)
            GWT's toolkit for complex browser-based applications includes flexible i18n tools.
          
        
        
        
      ECMAScript i18n API
            The ECMAScript Internationalization API provides key language-aware functionality for Javascript.
          
        
        
        
      Closure bidirectional text tools
            BiDi text handling is essential when you localize your application in right-to-left (RTL) languages including Arabic, Hebrew, Persian, and Urdu.
          
        
        
        
      CSS Mirroring for RTL layouts
            CSSJanus flips Cascading Style Sheets (CSS) between left-to-right and right-to-left orientations.
          
        
        
        
      BiDi Checker
            BidiChecker automates webpage testing, highlighting RTL-language errors.
          
        
        
        
      Pseudolocalization tool
            Generate a pseudotranslation of an application to quickly find potential localization problems.
          
        
        
        
      Handling dates, times, currencies, and more
            Common Data Local Repository (CLDR) provides the most extensive available set of key building blocks for the world's languages.
          
        
        
        
      PyICU
            Python applications can use ICU's i18n functionality with the  PyICU extension.