Systems
Ascendancy Creative Labs
Computers, Systems, Sinclair, ZX Spectrum - Ascendancy Creative Labs. Group active on ZX Spectrum and Amiga.
https://acl.narod.ru/
The Mad Guys' Tribute Page
Computers, Systems, Sinclair, ZX Spectrum - The Mad Guys' Tribute Page. A tribute to The Mad Guys demo group.
http://www.themadguys.de/
Demotopia
Comprehensive resource covering past and present activity on the ZX Spectrum demo scene.
https://zxdemo.org/
ZX Gate
Computers, Systems, Sinclair, ZX Spectrum - ZX Gate. An easy-to-build ZX 81/ZX Spectrum/Jupiter ACE/TRS80 using gate array logic.
https://zxgate.sourceforge.net/
Hardware changes and modifications.
Computers, Systems, Sinclair, ZX Spectrum - zx.yarek.com. Hardware changes and modifications.
http://zx.yarek.com/
Rebelstar Spectrum Emulation and Remakes
Spectrum Games, Roms, Emulators and Remakes
http://www.rebelstar.co.uk/
Sinclair ZX Spectrum site called The Speccy Zone
The Speccy Zone, Dedicated to everything Spectrum
http://thespeccyzone.emuunlim.com/
ZX Resource Centre - Sinclair ZX Interface 2 and Spectrum 128
Documents the Sinclair ZX Interface 2 and ROM cartridges (including building custom cartridges). Also documents how to build a SCART lead and keypad for the Sinclair ZX Spectrum 128, and how to extend 128 BASIC.
http://www.fruitcake.plus.com
The World of Spectrum
Computers, Systems, Sinclair, ZX Spectrum - The World of Spectrum. A huge archive of software, images and documentation for the Sinclair ZX Spectrum.
https://worldofspectrum.org/
ZX Box temp page
Computers, Systems, Sinclair, ZX Spectrum - ZX Box. A project which aims to allow the 48K ZX Spectrum to surf the net.
https://zxbox.sourceforge.net/
rakewell.com
Computers, Systems, Sinclair, Z88 - rakewell.com. Suppliers of Z88 and PC accessories.
http://www.rakewell.com/