ZEsarUX

ZEsarUX is an emulator by César Hernández Bañó that started as a ZX Spectrum emulator and grew to cover many machines built around the Z80 processor. Its name combines ZX, the author’s name and Unix.

It emulates the ZX80, ZX81 and every Spectrum model, clones such as the Pentagon, Chloe and Timex machines, and modern hardware like the ZX-Uno and ZX Spectrum Next. It also covers the Jupiter Ace, Cambridge Z88, Sinclair QL, SAM Coupé, Amstrad CPC and PCW, MSX, ColecoVision, SG-1000, Master System and Spectravideo, with some of these still less complete than the Spectrum.

ZEsarUX is known for its debugging tools, its ZX Desktop interface with many windows and its support for peripherals and storage devices. It is actively developed, and version 13.0 was released in June 2026 for Windows, macOS, Linux, FreeBSD, Haiku and Raspberry Pi. It is open source under the GNU GPL version 3.