Websites
https://lobste.rs -- like hackernews/ycombinator
https://notabug.org -- free code hosting, on gogs
https://riseup.net  -- privacy


Linux System and Network Performance Monitoring/Analysis

general performance analysis --
https://medium.com/netflix-techblog/linux-performance-analysis-in-60-000-milliseconds-accc10403c55
http://www.brendangregg.com/usemethod.html
https://medium.com/netflix-techblog/netflix-at-velocity-2015-linux-performance-tools-51964ddb81cf

traceroute and mtr --
https://www.digitalocean.com/community/tutorials/how-to-use-traceroute-and-mtr-to-diagnose-network-issues

ss -- 

Tech

http://www.retronet.net/
https://www.docker.com
https://www.ansible.com
https://gogs.io -- self-hosted git
irc server admin
dns records / domain name registration
ubuntu service management
Pure Bash Bible - https://github.com/dylanaraps/pure-bash-bible

GNU/Linux, *NIX Sysadmin

https://www.linode.com/docs/tools-reference/linux-system-administration-basics/
Debian Stretch Administrator's Handbook: https://l.github.io/debian-handbook/html/en-US/