libfive Studio is described as 'A minimalist GUI for solid modeling with the libfive kernel. It is a design environment based on Guile Scheme, and should be familiar to OpenSCAD users' and is an app in the Photos & Graphics category. There are more than 10 alternatives to libfive Studio for a variety of platforms, including Linux, Mac, Windows, Online / Web-based and Self-Hosted solutions. The best alternative is OpenSCAD, which is both free and Open Source. Other great apps like libfive Studio are CadQuery (Free, Open Source), Antimony (Free, Open Source), OpenJSCAD.org (Free, Open Source) and ImplicitCAD (Free, Open Source).
OpenJSCAD.org is a more up-to-date OpenJsCAD frontend where you can edit .jscad files either locally or online via JS editor (built-in). A few functions are available to make the transition from OpenSCAD to OpenJSCAD easier (OpenSCAD.
ImplicitCAD is a programmatic CAD program, implemented in Haskell. Unlike traditional CAD programs, programmatic CAD programs use text descriptions of objects, as in programming. Concepts like variables, control structures and abstraction are used, just as in programming.