Microsoft killed FoxPro in 2007. An independent project just revived it

Microsoft ended development of Visual FoxPro in 2007, leaving a large body of business software running on machines that only get older. FoxDev Studio, an independent open-source project, takes a different route from migration: it runs Visual FoxPro 9 applications as they are. Its authors describe the goal plainly: open the projects, forms and tables you already have and run them the way you remember — no rewrite, no conversion, no export step.

An IDE and a virtual machine

The project is built from two parts. The first is an IDE, an Electron application with a React interface: a project explorer, form and menu designers, a properties window, an editor and a debugger. The second is a virtual machine — a compiler and bytecode interpreter written in Rust and compiled to WebAssembly, which is what makes 64-bit machines possible.

Import is direct: the IDE reads a Visual FoxPro .pjx project and the .scx, .vcx, .mnx and .prg files it names, and writes the JSON documents it works on beside them.

FoxScript: lambdas and an HTTP server

On top of the existing language the project adds FoxScript: a LAMBDA block, a FoxScript namespace and two new value types. The point is to keep one runtime rather than a second language or a service standing beside the application.

A short server program shows the intent: SET LIBRARY TO "vfpencryption71.fll" ADDITIVE still loads an old 32-bit add-in library, and a lambda registered with FoxScript.Http.CreateServer() answers a route such as /api/v1/customers/:id.

Matching Visual FoxPro, not approximating it

The project's stated method is to settle behaviour by asking Visual FoxPro itself and matching its answer, rather than by reading a reference page and hoping. That matters because small differences break old applications: a column printed a character too wide, an event a moment late. Visual FoxPro's own Solution sample runs after import, with its 123 forms, 7 menus and 11 class libraries.

The IDE shell, the designers, the language and the data engine are done and used daily; reports are the milestone under way, and tables past two gigabytes already work. What cannot be carried over is listed by name — 16-bit overlays and the FoxPro 2.x screen designer are refused with a reason rather than left silent. Build App compiles a project to bytecode and writes an .fxa bundle, and the command-line runner foxvm executes programs with no interface at all.