Simple and opinionated tool to build your own magazine

https://zineland.github.io

Simple, customizable, and portable online handwriting recognition system

http://zinnia.sourceforge.net/

Handwriting recognition files for Zinnia (Tomoe data)

http://zinnia.sourceforge.net/

Barcode generator (library and utilities)

https://www.zint.org.uk/

Create/update ZIP files compatible with PKZIP

http://www.info-zip.org/Zip.html

Japanese zipcode tables. includes both 3/5 and 7 digits form

https://www.post.japanpost.jp/zipcode/

Produce .ZIP file from two other ones with the best compressed files

http://www.advsys.net/ken/utils.htm

Tool for inspecting the contents of a compressed archive

http://xanthippe.dyndns.org/Zipper/

User utilities for zisofs

Lightweight C library of portability wrappers and data structures

https://drobilla.net/category/zix/

Library for the Signal Private Group System

https://github.com/signalapp/zkgroup

Tool to manage keys and signatures for DNSSEC-zones

https://www.hznet.de/dns/zkt/

Fork of the zlib data compression library

https://github.com/zlib-ng/zlib-ng

Internet scanner

https://zmap.io/

C library for polynomial arithmetic

https://web.maths.unsw.edu.au/~davidharvey/code/zn_poly/

ZnapZend is a ZFS centric backup tool

https://www.znapzend.org/

CLI tool for querying DNS records with readable and colored output

https://github.com/znscli/zns

Updated timezone definitions

DNS notify sender written in C

http://www.morettoni.net/zonenotify.en.html

Manipulate archives of files in compressed form

Coordination Service for Distributed Applications

https://zookeeper.apache.org/

Z-Interpreter for X with full V6 support

http://www.logicalshift.demon.co.uk/unix/zoom/

Zopfli Compression Algorithm

https://github.com/google/zopfli

Fast cd alternative that learns your habits

https://github.com/ajeetdsouza/zoxide

Swiss army knife for the serious backup manager

https://github.com/fcorbelli/zpaqfranz

Zooming photo album generator

http://namazu.org/~satoru/zphoto/

ZFS pool I/O latency statistics

https://github.com/chadmiller/zpool-iostat-viz

ZFS based replication and failover solution

http://www.bolthole.com/solaris/zrep/

Destroys ZFS snapshots

https://www.fabiankeil.de/gehacktes/zsd/

The Z shell

http://www.zsh.org/

Tool for managing Zshell plugins inspired by Vundle

https://github.com/zsh-users/antigen

Fish-like autosuggestions for Zsh

https://github.com/zsh-users/zsh-autosuggestions

Additional completion definitions for Zsh

https://github.com/zsh-users/zsh-completions

Optimized and extended zsh-syntax-highlighting

https://github.com/zdharma-continuum/fast-syntax-highlighting

Curses-based tools for Zshell, e.g. multi-word history searcher

https://github.com/psprint/zsh-navigation-tools

Fish shell syntax highlighting for Zsh

https://github.com/zsh-users/zsh-syntax-highlighting

ZFS Snapshot Manager

https://zsm.rtfd.io/

Intel x86 only Super Nintendo Entertainment System (SNES) Emulator

https://www.zsnes.com/

Interactively transferring files to a remote machine while using ssh

http://zssh.sourceforge.net/

Fast real-time compression algorithm

https://facebook.github.io/zstd/

C++ header-only ZLib wrapper

https://github.com/mateidavid/zstr

A file transfer program

http://zsync.moria.org.uk/

Platform-independent object-oriented C++ threading library

http://zthread.sourceforge.net/

GUI toolkit heavily inspired by GTK

https://git.zrythm.org/zrythm/ztoolkit

Display ZFS dataset I/O in real time

https://github.com/asomers/ztop

Simple ncurses based pseudo-3D driving game

Utilities for searching in bzip2, gzip, lzip, and xz archives

http://www.nongnu.org/zutils/zutils.html

Easily and reliably transfer ZFS filesystems

https://github.com/allanjude/zxfer

C++ library for linear/matrix barcode recognition

https://github.com/zxing-cpp/zxing-cpp

ZFS Administration GUI

https://github.com/manoeldesouza