PCem is a comprehensive IBM PC/XT/AT and clone emulator written in C and C++. It emulates a vast range of vintage hardware, including x86 CPUs from 8088 to Pentium II (with both interpreter and dynamic recompilation backends for x86, x86-64, ARM, and ARM64), chipsets (Intel 430/440 series, VIA, SiS, OPTi, etc.), video cards (MDA, CGA, EGA, VGA, SVGA, Voodoo 1/2/3/Banshee), sound cards (AdLib, Sound Blaster, GUS, SID, etc.), storage controllers (IDE, SCSI, MFM, floppy), and networking (via bundled SLiRP). The GUI is built with wxWidgets and SDL2, providing configuration dialogs, status display, and shader management. The codebase is modular with a device registration system, I/O handler abstraction, memory mapping, and a plugin API for extensibility. It is actively maintained, cross-platform (Windows, Linux, macOS), and widely used for retro computing and software preservation.