Building Principia for Windows XP

- *Principia* is a physics-based sandbox game (like *The Powder Toy* or *Incredibots*) where players build and simulate interactive machines, vehicles, and contraptions. Its development fork is maintained by the Voxelmanip community. - Windows XP (2001–2014) is a decades-obsolete operating system that modern software and build tools (e.g. recent versions of Visual Studio, CMake, or the C++ standard library) no longer support. Keeping compatibility requires backporting code, using old SDKs, and working around dropped APIs. - This post documents the hands-on engineering effort to make a current C++ codebase compile and run on XP — a task that involves patching the build system, replacing modern system calls with older equivalents, and testing on actual or virtualized XP hardware. It is of interest mainly to retro-computing enthusiasts and software archaeologists who maintain legacy systems or study how dependencies age.