Desktop
Emacs
org-mode
tramp
Terminal (OSX)
Because the defaults are fine.
urxvt (Linux, Cygwin)
jq
yq
xmllint -xpath
Airfoil (OSX)
For sending audio to chromecast, airplay, and bluetooth
Server
vi
vi's fine for config files and quick edits. Code is edited on the desktop in emacs and pushed/pulled.