OpalOPAL (OPtimized Applicative Language) is a functional programming language first developed at the Technical University of Berlin.The most used programming languages Ruby Haskell F Sharp Elixir C Scala Swift Emacs Lisp Kotlin Perl R C Sharp Lua OCaml Java PowerShell Objective-C Apache Groovy Julia Dart Erlang Smalltalk Python Rust PHP Visual Basic … TypeScript JavaScript C++