zxian - a ZX Spectrum emulator (for Windows, written in C)

z80hai - a Z80 disassembler (for Windows, written in C)
smtap - a tool for managing ZX Spectrum TAP tape images
winzx - a Windows 98-themed ZX Spectrum custom tape loader
smloader - a minimalist ZX Spectrum custom tape loader
ZX Spectrum ROM source code, ready to assemble