Dart is programming language develop by Goolge October 10, 2011 right now the dart is very popular for mobile application development. It's also work for web framework (web app development) but especially uses for mobile app and game development. Flutter is open source software development kit which develop dart language.
Flutter is a free and open-source mobile UI framework created by Google and released in May 2017. In a few words, it allows you to create a native mobile application with only one codebase. This means that you can use one programming language and one codebase to create two different apps for IOS and Android.
On Mac
$ brew tap dart-lang/dart
$ brew install dart
On Linux
$ sudo apt-get update
$ sudo apt-get install apt-transport-https
$ sudo sh -c 'wget -qO- https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -'
$ sudo sh -c 'wget -qO- https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > /etc/apt/sources.list.d/dart_stable.list'
Then install the Dart SDK
$ sudo apt-get update
$ sudo apt-get install dart