TypeScript
TypeScript is a typed superset of JavaScript created by Microsoft to bring all of the advantages of object orientation and classes into JavaScript, as well as strongly typed variables. It can be used on any project, be it frontend, backend or for scripts with a palpable increase in cohesion and code correctness through the use of types and formal declarations. For the programmer it brings increased security in the development since the code is constantly being checked to make sure everything fits together nicely and with the proper types. For the final product it ensures a result with less flaws and bugs given that those might have been detected earlier by type checking.