OCR program implemented as filter

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

Utility for manipulating ODS-2 filesystems

https://www.goatley.com/hunter/

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/

Run Llama 2, Mistral, and other large language models

https://ollama.com/

Library that provides thread building blocks

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

Regular expressions library compatible with POSIX/GNU/Perl

https://github.com/kkos/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))

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

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

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 Chinese Convert library and utilities

https://github.com/BYVoid/OpenCC

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/

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://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 11 FreeBSD binary

http://openjdk.java.net/

OpenJDK 13 FreeBSD binary

http://openjdk.java.net/

OpenJDK 17 FreeBSD binary

http://openjdk.java.net/

OpenJDK 18 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://www.openjpeg.org/

Open-source JPEG 2000 codec

https://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/

Network Time Protocol (NTP) daemon

https://www.openntpd.org/