There are 2 repositories under sinclair topic.
Project for capturing vintage, classic, aka old computer schematics in KiCad.
ZEsarUX - ZX Second-Emulator And Released for UniX
Visual inspection tool for .dsk Spectrum/Amstrad disk images
zx spectrum 128 emulation on stm32f407 + Grant Searle's CP/M system port ili9341 16 bit display
Level 9 interpreter for Spectrum Next
A cross platform retro 8-bit image, video, Sinclair ZX Spectrum output and artwork tool.
Spectrum Next BMP tools
An old-school remake of the ZX Interface 2 with some modern tweaks - mainly by integrating bank switching into the interface itself. Everything done with basic logic chips and components, no magic black boxes to be found anywhere!
My CS:GO cheat, written with performance in mind.
C layer 2 graphics API for Spectrum Next
Simple UDG (User Defined Graphics) character editor for Sinclair ZX Spectrum BASIC.
ZX-Uno port for MEGA65 delivering a fully fledged ZX Spectrum 48k and 128k
Arduboy clone of the ZX Spectrum classic Jet Pac
Simple ROM cartridge for Sinclair ZX Interface 2.
OpenHAB binding for EWPE Smart powered devices (Gree, Sinclair, etc)
Source for various Spectrum-related tools from John Elliot's web site.
BASIC source code for Rebelstar Raiders, a 1984 ZX Spectrum game
ZX Microdrive cartridge .MDR file cruncher
The zxspec48-app is an empty SDCC application template for ZX Spectrum 48K.
ZX81 External 16K/32K RAM interface with WRX hi-res support