software for Unix, &c.

Only free software is listed on this page, unless otherwise marked (≠).

These are mostly command-line tools (though some may also support graphical interfaces, and other operating systems). Software intended for use primarily in a GUI environment (e.g. the X window system) is marked with a G.

unfiled

Void Linux
a simple Linux distribution which does not use systemd – (I almost left Linux after Debian and Arch succumbed… but I found Void, an oasis of sanity in the madness of Linux)
Remind
language and interpreter for creating reminders and calendars
TestDisc & PhotoRec
data recovery software
tmux
terminal multiplexer (in preference to screen)
Plan 9 from User Space
the successor to Unix, ported to Unix
LillyPond
high-quality music printing (for European classical notation)
MuPDF
G : small/fast PDF (& XPS) viewer
inotify-tools & incron
monitor and act upon inotify filesystem events

text

mawk
a very fast (if not the fastest) implementation of awk (often faster than GNU sed!)
ripgrep
fastest of the ack-style search tools
xsv
for indexing, slicing, analyzing, splitting and joining CSV files
fzf
a general-purpose command-line fuzzy finder (many other selectors exist but fzf does more)
icdiff
improved coloured side-by-side diff
ShellCheck
a static analysis and linting tool for sh/bash scripts
Pandoc
a universal document converter
peg/leg
recursive-descent PEG parser generators for C
ANTLR
ANother Tool for Language Recognition (also: ANTLRWorks GUI)
Code Browser
G : a fast/functional/clean folding text editor (supports elastic tabstops)
Textadept
G : a fast, minimalist, Lua-extensible text editor (supports elastic tabstops)
Geany
G : text editor with a small and fast IDE
Meld
G : a visual diff and merge tool
FontForge
G : outline font editor
Microsoft ClearType fonts
≠ : a script to install the excellent fonts included with Windows Vista (specifically Candara & Consolas)

network

monolith
saves local copy of web page as single html file
HTTPie
a command line HTTP client for painless debugging
HTTrack
website mirroring; a welcome alternative to wget
Claws Mail
G : fast (relatively lightweight) and extensible e-mail client
Transmission
G : BitTorrent client

system

sxhkd
bind commands to input events (keyboard, mouse, &c.)
htop
an interactive process viewer (like top)
ranger
terminal file manager with Miller columns
ncdu
fast disk usage analyzer with an ncurses interface
earlyoom
user space oom killer (because the kernel’s waits too long)
PowerTOP
measure power consumption of running software
xdotool
G : command-line tool to simulate keyboard/mouse input, move/resize windows, &c.
AutoKey
G : desktop automation utility (text substitution, hotkeys, scripts)

audio/video

SoX
digital audio conversion tools (with accurate resampling)
abcde
comprehensive CD encoder
mpg123
small, fast mp3 console-based player for files and streams
Music Player Daemon
audio server
mpv & VLC
G : media players (mpv = best quality; vlc = wider support & DVD menus)
gmusicbrowser
G : music browser/player for large collections
EasyTAG
G : tag viewer/editor for most audio file formats
Ardour
G : digital audio workstation
Pd (Pure Data)
G : real-time graphical programming environment for audio, video, and graphical processing
SuperCollider
G : environment and programming language for real time audio synthesis and algorithmic composition
Processing
G : programming language and development environment for visual arts

pixels

gphoto
manipulate digital cameras
GraphicsMagick
image manipulation tools (originally forked from ImageMagick)
scrot
G : screen shot (capture display state)
cropgui
G : minimal GUI for lossless JPEG cropping
darktable
G : photography workflow application; enhance/develop raw images
Scan Tailor
G : interactive post-processing tool for scanned pages

illustration

Asymptote
vector graphics language that provides a natural coordinate-based framework for 2D and 3D technical drawing
Context Free
environment for editing, rendering, and exploring images generated from design grammars
Eukleides
a concise geometry drawing language