KDE universal document viewer

https://okular.kde.org

Ultimate Oldschool PC Font Pack

http://int10h.org/oldschool-pc-fonts/

Library that provides thread building blocks

https://software.intel.com/oneapi/onetbb

A BSDL Regular Expressions library compatible with POSIX/GNU/Perl

http://www.geocities.jp/kosako3/oniguruma/

Open Neural Network eXchange

https://onnx.ai https://github.com/onnx/onnx

Open-source COBOL compiler

http://www.opencobol.org/

Motif X11 Toolkit (industry standard GUI (IEEE 1295))

http://www.opengroup.org/openmotif/

Clean and modern sans-serif typeface

https://www.opensans.com

Open VMware tools for FreeBSD VMware guests

https://github.com/vmware/open-vm-tools

Japanese Text-to-speech system using HTS-engine and Mecab

http://open-jtalk.sourceforge.net/

Software implementation of the OpenAL specification

http://kcat.strangesoft.net/openal.html

Chemistry file translation program

http://openbabel.sourceforge.net/

Optimized BLAS library based on GotoBLAS2

https://github.com/xianyi/OpenBLAS

Small, fast, standards compliant, extensible window manager

http://openbox.org/

Open Chinese Convert library and utilities

https://github.com/BYVoid/OpenCC

Open Computing Language (OpenCL) specifications V2.2 (header files)

OpenCORE implementation of AMR Narrowband & Wideband speech codec

http://sourceforge.net/projects/opencore-amr/

Middleware framework for smart card terminals

https://github.com/OpenSC/openct

File format for compression of 3D triangle meshes

https://sourceforge.net/projects/openctm/

Open Source Computer Vision library

http://www.opencv.org

Ming and Kai face of OpenDesktop fonts

http://opendesktop.org.tw

DKIM library and milter implementation

http://opendkim.org/

Port of OpenDoas: a portable version of OpenBSD's doas

https://github.com/Duncaen/OpenDoas

High dynamic-range (HDR) image file format

https://www.openexr.com/

Enterprise instant messaging server

https://www.igniterealtime.org/projects/openfire/index.jsp

Universal utility for programming FPGA

https://github.com/trabucayre/openFPGALoader

Fast and powerful code search and cross-reference engine

https://opengrok.github.io/OpenGrok/

Cisco implementation of H.264 codec

http://www.openh264.org/

Complex IPMI management software

http://openipmi.sourceforge.net/

Object-oriented SGML/XML parser toolkit and DSSSL engine

http://www.netfolder.com/DSSSL/

OpenJDK 11 FreeBSD binary

http://openjdk.java.net/

OpenJDK 17 FreeBSD binary

http://openjdk.java.net/

OpenJDK 21 FreeBSD binary

http://openjdk.java.net/

OpenJDK 24 FreeBSD binary

http://openjdk.java.net/

Java Development Kit 8

https://openjdk.java.net/

OpenJDK 8 FreeBSD binary

http://openjdk.java.net/

Java Runtime Environment 8

https://openjdk.java.net/

Open-source JPEG 2000 codec

https://code.google.com/p/openjpeg/

Open-source JPEG 2000 codec

http://www.openjpeg.org/

Open-source implementation of JPEG2000 Part-15

https://github.com/aous72/OpenJPH

Open source LDAP client implementation

https://www.OpenLDAP.org/

Open source LDAP server implementation

https://www.OpenLDAP.org/

Open source LDAP client implementation

https://www.OpenLDAP.org/

Open source LDAP server implementation

https://www.OpenLDAP.org/

High Performance Message Passing Library

https://www.open-mpi.org/

Network Time Protocol (NTP) daemon

https://www.openntpd.org/

Tools to accurately transfer 3-D geometry between applications

https://www.rhino3d.com/opennurbs

Implementation of the PGM reliable multicast protocol

https://code.google.com/p/openpgm/

Detects vulnerabilities in running applications

https://github.com/baidu/openrasp

Software to control a multitude of (a)RGB devices

https://openrgb.org