Refactoring and productivity extension by JetBrains called Resharper provides features for code refactoring, navigation, formatting and analysis. It allows abstraction of code through techniques like encapsulating fields and generalizing types. Refactoring techniques also break code into more logical pieces through componentization and extracting classes/methods. Naming conventions can be improved by moving or renaming code elements. Resharper supports languages like C#, JavaScript, HTML and provides code generation, navigation shortcuts and assists with coding best practices.