OpenCL Installable Client Driver

https://github.com/OCL-dev/ocl-icd

Round clock application for X

OCR program implemented as filter

http://www.gnu.org/software/ocrad/ocrad.html

Customized version of the Source Code Pro font

https://github.com/nathco/Office-Code-Pro

Monospaced font based on Artwiz Snap

https://sourceforge.net/projects/osnapfont/

Help you update your snort rules after each update

http://oinkmaster.sourceforge.net/

Ultimate Oldschool PC Font Pack

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

Regular expressions library compatible with POSIX/GNU/Perl

https://github.com/kkos/oniguruma

VoIP abstraction library

http://opalvoip.org/

Open-source COBOL compiler

http://www.opencobol.org/

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

https://motif.ics.com/

Clean and modern sans-serif typeface

https://www.opensans.com

Open VMware tools for MidnightBSD VMware guests

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

3D positional spatialized sound library

http://www.openal.org/

Software implementation of the OpenAL specification

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

Chemical toolbox designed to speak the many languages of chemical data

https://openbabel.org/wiki/Main_Page

Optimized BLAS library based on GotoBLAS2

https://github.com/xianyi/OpenBLAS

Small, fast, standards compliant, extensible window manager

http://openbox.org/

Open Crypto Development Kit

http://www.gnutls.org/

Open Computing Language (OpenCL) specifications V3.0 (header files)

https://github.com/KhronosGroup/OpenCL-Headers/

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

Open Source Computer Vision library

https://www.opencv.org/

Open Source Computer Vision library

https://www.opencv.org/

DKIM library and milter implementation

http://opendkim.org/

High dynamic-range (HDR) image file format

https://github.com/AcademySoftwareFoundation/openexr/

Enterprise instant messaging server

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

Fast and powerful code search and cross-reference engine

http://opengrok.github.io/OpenGrok/

Cisco implementation of H.264 codec

https://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 7 FreeBSD binary

http://openjdk.java.net/

OpenJDK 8 FreeBSD binary

http://openjdk.java.net/

Open-source JPEG 2000 codec

https://www.openjpeg.org/

Open-source JPEG 2000 codec

https://www.openjpeg.org/

Open source LDAP client implementation

https://www.OpenLDAP.org/

Open source LDAP client implementation with SASL2 support

http://www.OpenLDAP.org/

Open source LDAP server implementation

https://www.OpenLDAP.org/

Open Multi-Processing runtime for LLVM/Clang

http://openmp.llvm.org/

High Performance Message Passing Library

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

Implementation of rsync with a BSD (ISC) license

https://github.com/kristapsdz/openrsync

Libraries and utilities to access smart cards

https://github.com/OpenSC/OpenSC/wiki

Open-source implementation of the Service Location Protocol

http://www.openslp.org/

This package is a collection of SGML/XML tools called OpenSP

http://openjade.sourceforge.net/doc/

Graphical password applet for entering SSH passphrase

http://www.jmknoble.net/software/x11-ssh-askpass/

The portable version of OpenBSD's OpenSSH

https://www.openssh.com/portable.html

TLSv1.3 capable SSL and crypto library

https://www.openssl.org/

UPS daemon for some Belkin UPS's

http://frmb.org/openupsd.html

Secure IP/Ethernet tunnel daemon

https://openvpn.net/community/

Optimizer for PNG files

http://optipng.sourceforge.net/