Neko Project 21/W

Neko Project 21/W (NP21/W) is a PC-9800 series emulator for Windows developed by SimK. It is based on Neko Project 21, the PC-9821 version of Yui’s Neko Project II, and adds many features so that it can emulate the mid to late PC-98 era, from around 1993 onwards.

It emulates both the PC-9801 and the later PC-9821 machines, with 32-bit and 64-bit builds of each. Additions over the original include a faster x86 CPU core with FPU support, CD-ROM drives, IDE and SCSI hard disks, several sound boards, window accelerator boards, a network adapter and shared host folders. It can run MS-DOS, Windows 3.1, Windows 95/98 and Windows NT and 2000 inside the emulator, and there are HAXM and WHPX builds that use the host CPU’s virtualisation support.

Neko Project 21/W is freeware and comes with its source code. It is actively developed: version 0.86 rev105 was released on 27 September 2026, alongside a rev106 beta. It only runs on Windows 2000 and later; on other systems NP2kai offers much of the same emulation.

The official downloads are hosted on Google Drive and cannot currently be tracked automatically, so this page has no download archive yet. Get the latest version from the official Neko Project 21/W site.