Platforms
Purism
System76
Raptor Computing Systems
Origin
Dell
NitroPad X230 (refurbished ThinkPad)
Insurgo (refurbished ThinkPad)
Minifree (refurbished ThinkPad)
Technoethical (refurbished ThinkPad)
Olimex DIY laptop

OSes
Qubes OS
OpenBSD
Linux Kodachi
Arch Linux
Gentoo Linux
Subgraph OS (still in alpha)
Kali Linux
BlackArch Linux
Bodhi Linux
Alpine Linux
AntiX Linux
PureOS
Ubuntu-Mate
Debian
Fedora
Parabola
Trisquel

Firmware
Libreboot
Coreboot
LinuxBoot
OpenWrt
LibreCMC

Routers/Peripherals
Pepwave Surf SOHO
Libre Router (refurbished Netgear)
Vikings WNDR3800 (refurbished Netgear)
Nitrokey
Librem Key

VoIP software
Wire
Jitsi Meet

Astro: Tools
FUNTOOLS pages
NASA's HEASARC
Software carpentry
Shell Tips
ASCL
VisIt
Julia

Astro: Journals, booklets, papers
SCI-HUB
Monthly Notices
Astronomy & Astrophysics
NRL Plasma Formulary
ArXiv; ArXiv mirrors

Astro: Net resources
Astronomy conferences
SKA Science
ESO Press Releases
ASTRON News
MIT News
Astrobites
Les Actualités Astronomie | Futura Sciences
Centaurus A project pages
SatTrackCam

Technology/Security: Net resources
The Register
The Guardian
Bleeping Computer
Schneier on Security
Krebs on Security
Ross Anderson's Homepage
Unix Sheikh's Website
OWASP Top 10
OWASP Mobile Top 10
IETF | RFCs
Phoronix
Lifewire
Bunnie's blog
Matthew Garrett: Firmware security, why it matters and how you can have it
Numberphile
Computerphile