PCem is a vintage IBM PC/XT/AT/386/486/Pentium emulator that prioritizes hardware-level accuracy over performance. It emulates a vast range of CPUs (8088 through Pentium II, K6, Cyrix), chipsets (Intel 430/440 series, VIA, SiS, OPTi, etc.), video cards (CGA, EGA, VGA, SVGA, Voodoo 1-3, ATI Mach64, S3 Virge, and many more), sound cards (AdLib, Sound Blaster, Gravis Ultrasound, AWE32, OPL, reSID, etc.), storage controllers (IDE, SCSI, MFM, floppy), and networking (NE2000, SLiRP). The emulator uses a dynamic recompiler (codegen) with host backends for x86, x86-64, ARM, and ARM64 to achieve usable performance on modern hardware. It provides two parallel GUI frontends (wxWidgets and Qt), both using SDL2 for video and input, and supports a plugin system for extending emulated hardware. The codebase is written primarily in C with some C++ components, built with CMake and Clang, and targets Windows, Linux, and macOS.