HyperFun is described as 'simple specialized high-level programming language. It is intended for modeling geometric objects and their internal volumetric properties (color, material density and others)' and is an app in the Development category. There are more than 10 alternatives to HyperFun for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Self-Hosted solutions. The best alternative is FreeCAD, which is both free and Open Source. Other great apps like HyperFun are OpenSCAD (Free, Open Source), BRL-CAD (Free, Open Source), CadQuery (Free, Open Source) and Antimony (Free, Open Source).
BRL-CAD is a powerful cross-platform open source solid modeling system that includes interactive geometry editing, high-performance ray-tracing for rendering and geometric analysis, image and signal-processing tools, a system performance analysis benchmark suite, libraries for...
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.