jf Open Huninn by justfont

https://justfont.com/huninn/

Simulates a jigsaw puzzle and illustrates the use of clipping paths

http://gap.nongnu.org/jigsaw/

Java source to byte-code compiler made available by IBM

http://jikes.sf.net/

English to Japanese dictionary for GNUstep

http://www.eskimo.com/~pburns/Dictionaries/

Command line client for posting JustJournal entries

https://www.justjournal.com/

Jerry's command-line LiveJournal.com entry system

http://umlautllama.com/projects/perl/#jlj

Jim Knoble's font package for X

http://www.jmknoble.net/fonts/

Java access to native shared libraries

https://github.com/twall/jna

Joe's Own Editor

https://sourceforge.net/projects/joe-editor/

Dynamic web content management system (CMS)

https://www.joomla.org/

IJG's jpeg compression utilities

http://www.ijg.org/

SIMD-accelerated JPEG codec which replaces libjpeg

https://libjpeg-turbo.org/

View and/or control a remote PC

http://jrdesktop.sourceforge.net/

JSON (JavaScript Object Notation) implementation in C

https://github.com/json-c/json-c/wiki

JSON (RFC 4627) interface for Glib

http://live.gnome.org/JsonGlib

JSON reader and writer library for C++

https://github.com/open-source-parsers/jsoncpp

General purpose dynamic array

http://judy.sourceforge.net/

Humanist sans-serif font

https://www.theleagueofmoveabletype.com/junction

Unicode/MUFI OpenType font for medievalists (Latin, IPA, Runic, Greek)

http://junicode.sourceforge.net/

Regression testing utility for use with the Java(TM) Language

http://www.junit.org/

The editor which sucks less

http://www.mirbsd.org/jupp.htm

Makefile framework

http://svn.netlabs.org/kbuild

Free Unicode font for Sinhala script

http://www.kaputa.com/slword/kaputaunicode.htm

Serial and network communications package

https://www.kermitproject.org/

Library for registering keyboard shortcuts

https://github.com/engla/keybinder

Library for registering keyboard shortcuts

https://github.com/engla/keybinder

Extra modules and scripts for CMake

https://quickgit.kde.org/?p=extra-cmake-modules.git

Khmer OS fonts

https://sourceforge.net/projects/khmer/

Browser based analytics and search interface to ElasticSearch

https://www.elastic.co/products/kibana

High performance authoritative-only DNS server

https://www.knot-dns.cz/

Knot2 lib (required by knot-resolver)

https://www.knot-dns.cz/

Web application framework for writing web APIs in C

http://www.kore.io/

Authentication system developed at MIT, successor to Kerberos IV

http://web.mit.edu/kerberos/

Official AT&T release of KornShell 93

http://www.kornshell.com/

Testing framework for infrastructure software

https://github.com/jmmv/kyua/

Cracks SAMBA or Windows NT passwords

Linux Audio Developer's Simple Plugin API

http://www.ladspa.org/

Fast MP3 encoder kit

http://lame.sourceforge.net/

Linear Algebra PACKage

http://www.netlib.org/lapack/

Tetris-like game for GNUstep

http://www.nongnu.org/gap/lapispuzzle/

Session management system for JACK audio applications

http://www.nongnu.org/lash/

Image viewer and slideshow application

http://gap.nongnu.org/

LaTeX service for GNUstep

http://www.roard.com/latexservice/

Sans-serif type family

http://www.latofonts.com

Microsoft .CABinet file creator

http://ohnopub.net/~ohnobinki/lcab/

Light Color Management System -- a color management library

http://www.littlecms.com/

Accurate, fast, and small-footprint color management engine

https://www.littlecms.com/

Maintain DNS zones using an LDAP directory

https://github.com/bklang/ldap2dns

Utility for patching LDAP directories using LDIF files

https://launchpad.net/ldapdiff

Ldconfig compatibility script