System Shock at Wikipedia
TTLG's System Shock 1 Fansite Hub
YouTube - LGR - System Shock - DOS PC Game Review

TSSHP (The System Shock Hack Project) a project to reverse-engineer and recode (from scratch, but using the original datafiles) the 3D role-playing / shooter games from Looking Glass (System Shock and the Ultima Underworlds)
Abysmal is a project that aims to recreate an engine for System Shock 1 and Ultima Underworld that can run those games with the original data files.

GitHub - Toxicfrog/ss1edit Editing and data viewing tools for System Shock 1.