Liberty BASIC

Liberty BASIC is a commercial dialect of the BASIC programming language bundled with its own integrated development environment for Windows. Carl "Gunner" Gundel wrote it and his company, Shoptalk Systems, published the first release in 1991. The system runs programs through an interpreter that was itself developed in Smalltalk. Source code is turned into a tokenized file with the extension TKN, which a small executable of the same name then runs, so Liberty BASIC does not compile to native machine code. The language is deliberately simple: only numeric and string data types are supported, variables need no declarations, a trailing dollar sign marks a string, and arrays of one or two dimensions are the only data structure besides the STRUCT used for calling DLLs. Its distinctive idea is to treat windows like files, so a program opens a window, a disk file, a DLL or a serial port with the same OPEN command and then prints text or commands to it. It supports both procedural programming in a default main window and event-driven programming with graphical windows, buttons, menus and text boxes. The last published release, version 4.5.1, appeared in June 2018, and the community has produced tools such as the FreeForm GUI editor and the alternative implementation LB Booster.