Utilities to help manage documentation for Yelp and the web

https://wiki.gnome.org/Apps/Yelp/Tools

DocBook XSLT stylesheets for yelp

http://www.gnome.org/

Free (GPL) encoder and decoder for the yEnc Usenet file format

http://www.yencode.org/

Amateur Radio curses based logging program

https://fkurz.net/ham/yfklog.html

SMT solver

https://yices.csl.sri.com/ https://github.com/SRI-CSL/yices2/

Convert between YAML, TOML, JSON, and HCL

https://github.com/sclevine/yj

Command line tool that converts YAML to JSON

https://github.com/bruceadams/yj

Yubico C client library

https://developers.yubico.com/yubico-c-client/

Library and tool for personalization of Yubico's YubiKey

https://developers.yubico.com/yubikey-personalization/

Youtube videos downloader

https://github.com/kkdai/youtube

Command-line YAML and XML processor, jq wrapper for YAML/XML documents

https://kislyuk.github.io/yq/

Improved version of Icculus Quake II

https://www.yamagi.org/quake2/

Command-line program for downloading videos from various platforms

https://github.com/yt-dlp/yt-dlp

Unpack data in MS Outlook TNEF format

https://github.com/Yeraze/ytnef

Yubico PIV tool

https://developers.yubico.com/yubico-piv-tool/

Multi-lingual Unicode text editor with TTF support

https://www.yudit.org/

The Yahoo! JavaScript and CSS Compressor

http://developer.yahoo.com/yui/compressor/

Encrypted peer-to-peer IPv6 UDP messaging terminal

https://github.com/yamafaktory/yume

Tool to decode yEnc encoded files

http://yydecode.sf.net/

Fastest JSON library in C

https://github.com/ibireme/yyjson

Compact Finite Element Analysis System

https://en.z88.de/

Zangband (Zelazny Angband) with color, X11 support

http://www.zangband.org/

Maintain and replicate ZFS snapshots

https://github.com/Jehops/zap

Dynamically typed N-D expression system based on xtensor

https://github.com/xtensor-stack/zarray

Nibbles-like multiplayer game

https://zatacka.sourceforge.net/

ZBar barcode reader

http://zbar.sourceforge.net

Compressed file format that splits the file into independent chunks

https://github.com/zchunk/zchunk

Fast CLI DNS lookup tool

https://github.com/zmap/zdns

Source port for Doom-engine games

https://www.zdoom.org/

Z39.50/SR server software

http://www.indexdata.dk/zebra/

Event logging framework - engine

https://wiki.gnome.org/Projects/Zeitgeist

Display GNOME dialogs from the command line

Simpler web photo gallery

https://www.zenphoto.org/

Network virtualization everywhere

https://github.com/zerotier/ZeroTierOne/

Zetaback ZFS backup and recovery management system

https://github.com/omniti-labs/zetaback/

Simple way of maintaining zfs snapshots using the periodic system

http://www.neces.com/blog/technology/integrating-freebsd-zfs-and-periodic-snapshots-and-scrubs

ZFS Snapshot Replication Script

http://blogs.sun.com/constantin/entry/useful_zfs_snapshot_replicator_script

View ZFS snapshot differences via a web browser

https://github.com/j-keck/zfs-snap-diff

Tool to sieve ZFS snapshots as per given spec a la 'pdumpfs-clean'

http://github.com/knu/zfs-snapshot-clean

Automatic ZFS snapshot management tool

http://marcin.studio4plus.com/en/zfs-file-history/howto.html

Display human-readable ZFS statistics

http://www.vx.sk/zfs-stats/

Display human-readable ZFS statistics

https://druidbsd.sourceforge.net/download.shtml

Simple sh script to make zfs rolling snaphosts with cron

https://github.com/graudeejs/zfSnap/

Portable performant script to make rolling ZFS snapshots easy

https://github.com/zfsnap/zfsnap

OpenSolaris-compatible auto snapshotting for ZFS

http://github.com/bdrewery/zfstools

Zoner's Half-Life compile tools

http://zhlt.info/

Small emacs-like text editor

http://www.gnu.org/software/zile/

Distributed computing project

http://zillion.sourceforge.net/

Tools for handling ZIM files

https://github.com/openzim/zim-tools

Image-generator that uses ASCII input files to create PNGs/EDFs

https://zimg.sourceforge.net/