OpenCyc / News: Recent posts

Cyc Training - Spring 2009

======== Course Announcement =========

What: Cyc 101 - Intro to Cyc
When: May 11-13, 2009 (3 days)
Where: Cycorp headquarters in Austin, Texas
Total Cost (including lunches): $1,900*

This course will familiarize you with Cyc's powerful knowledge representations and tools and will provide ample opportunity to use those tools to represent semantic information in Cyc.

Cyc 101 is a three-day workshop, balancing focused lectures with hands-on practice to reinforce the concepts and techniques being presented. The course aims to have you spend as much time as possible interacting with Cyc. Upon completing the class, you should feel comfortable navigating Cyc's huge knowledge base (KB) and have a strong basic understanding of how to find and make use of relevant KB content. You will also learn how to extend Cyc's KB by entering simple facts and rules using the Cyc KB browser interface. ... read more

Posted by Larry Lefkowitz 2009-01-09

We'll be right back ...

We're working on a new release of OpenCyc with even more content, greater platform portability, better performance, and improved reliability. Sorry we don't have a release available at the moment, but keep your eyes on this space for news of the new release. In the meanwhile, you can still access OpenCyc content via our semantic web endpoints (at and web services (at Thanks for your understanding and patience.

Posted by Larry Lefkowitz 2009-01-09

Cycorp is pleased to announce the Cyc ATP Challenges at CASC


Cyc ATP Challenges at CASC
<link rel="shortcut icon" href="">


Cycorp is pleased to announce the Cyc ATP Challenges at CASC!




<a href="">Cyc</a>

knowledge base comprises hundreds of thousands of
concepts, interrelated through millions of formal
assertions representing a broad scope of common-sense
knowledge. As such, Cyc provides a foundation for semantically-aware
solutions in a wide range of domains.... read more

Posted by Larry Lefkowitz 2008-08-08

OpenCyc now w/links to WordNet

The latest release of OpenCyc (1.0.2) contains links between thousands of Cyc concepts and the corresponding WordNet synsets.

Posted by Larry Lefkowitz 2006-10-27

OpenCyc 1.0 Released

OpenCyc 1.0 is now available and it's bigger and better than ever.
OpenCyc 1.0 includes the entire Cyc ontology containing hundreds of
thousands of terms, along with millions of assertions relating the terms
to each other, forming an upper ontology whose domain is all of human
consensus reality. The ontology is freely available for research or
commercial use under the Apache License, Version 2.0.... read more

Posted by John De Oliveira 2006-08-10

First Annual Cyc Prizes

SUBJECT: Cycorp announces the first annual Cyc prizes
MEDIA CONTACT: John De Oliveira, (512) 342-4000

Cycorp CEO Doug Lenat announces The 2006 Cyc Prize Competition, annual awards for publications and proposals involving OpenCyc and/or ResearchCyc. Winners will be announced March 7, 2006.

Begun in 1984 by Dr. Lenat, a former Stanford professor and MCC principal scientist, Cyc is a huge knowledge base of assertions about the everyday world, expressed in a logical formalism so machines can easily perform automatic deduction on them. OpenCyc is the open source version of the Cyc technology, including its ontology of terms and taxonomic information about each. ResearchCyc is a more inclusive version of the technology available at no charge to both academia and industry for R&D purposes. See read more

Posted by John De Oliveira 2005-10-17

OpenCyc v0.9 Now Available, For Windows and Linux

OpenCyc is the open source version of the Cyc(r) technology, the world's largest and most complete general knowledge base and commonsense reasoning engine. Version 0.9 is the first OpenCyc release in over two years and it is FIVE TIMES LARGER than the previous version.

OpenCyc now contains over 47,000 concept terms and over 300,000 facts (163MB compressed), all represented formally using CycL, a predicate-calculus-like language. Inference is also twice as fast, on average, as in the previous version, despite the increased size. ... read more

Posted by John De Oliveira 2005-03-03

Announcing OpenCyc release 0.7 for Linux and Windows

OpenCyc is the open source version of the Cyc(r) technology, the world's largest and most complete general knowledge base and commonsense reasoning engine. OpenCyc can be used as the basis for a wide variety of intelligent applications.

The OpenCyc Knowledge Base and its accompanying freely distributable binary
OpenCyc Knowledge Server are now available for Windows NT/2000/XP. Previously only available on Linux, version 0.7 for Linux and Windows also now includes an integrated hierarchical task network planner, improved inferencing capabilities, support for remote connections, and an early version of a Java-based ontology grapher. New documentation includes the first release of the Ontological Engineer's Handbook, new online tutorials for inference and efficient OE, and a one-hour beginner's walkthrough of the knowledge entry process.... read more

Posted by John De Oliveira 2002-12-17

OpenCyc 0.7.0 preview

Our three public OpenCyc servers at:

are running Opencyc version 0.7.0 which will be available soon in both Linux and Win32 versions.

Posted by Stephen L. Reed 2002-08-26 / #opencyc

Our OpenCyc developer community has an active IRC (Internet Relay Chat) channel hosted by /join #opencyc

Posted by Stephen L. Reed 2002-06-10

OpenCyc 0.6 released for Linux i386

OpenCyc is the open source version of the Cyc(r) technology, the world's largest and most complete general knowledge base and commonsense reasoning engine. OpenCyc can be used as the basis for a wide variety of intelligent applications.

Today release 0.6 is available for linux on i386 platforms. Discuss it on / #opencyc.

Public browsing servers are: and read more

Posted by Stephen L. Reed 2002-04-04

Project Update: March 22, 2002

Project Update: March 22, 2002

We're closing in on our deadline of March 31 at 11:59:59. While at times this project has had to temporarily take the back seat to other more urgent company demands, we currently have a lot of #$Cyclists testing the latest build, adding last minute features and helping polish up some of the documentation. It's going to be close. At this point, the bets are on making this release. If we miss, it won't be by much this time. Maybe a week. But we're still aiming for the 31st.... read more

Posted by John De Oliveira 2002-03-23

Project Update: Feb. 5, 2002

Below is an OpenCyc project update in the form of a Q&A with Cycorp Founder Doug Lenat:

Q: Is Cycorp committed to releasing OpenCyc?

A: 100%. This has been in our plan since Cyc's inception in 1984. Two of the major uses of Cyc are (1) as a semantic kernel which others can extend, for their own projects and applications, and (2) as a sort of semantic glue or interlingua which others can use to align their ontology to and thereby interrelate their ontology with everyone else's which has similarly aligned with Cyc. OpenCyc is that kernel, that interlingua. We have several members of our technical staff working fulltime on this; our delay in releasing OpenCyc is in no way related to a lack of commitment or change in heart.... read more

Posted by John De Oliveira 2002-02-05

Project Update: Dec. 10, 2001

The 1.0 release of OpenCyc will not be out before the end of 2001, as previously projected. While work continues in earnest toward a release, a new release date is not being given at this time. A more detailed update will be given early in the new year, including a Q&A with Cycorp's Founder Doug Lenat in which he reaffirms Cycorp's commitment to release OpenCyc as soon as possible.

If you would like to contribute time to testing the release, please email John De Oliveira at read more

Posted by John De Oliveira 2001-12-10

Project Update

Sept. 24: A recent review of knowledge base content by OpenCyc ontologists has revealed that certain constants have incomplete minimal definitions. A minimal definition for a constant should include:

- all significant taxonomic assertions (e.g. those using #$isa, #$genls, #$genlPreds, etc.);

- all constraining assertions for predicates and denotational functions (e.g. those using #$argIsa, #$argGenls, #$resultIsa, #$resultGenls);... read more

Posted by John De Oliveira 2001-09-24

OpenCyc Project Update

Update on activity related to release 1.0 of OpenCyc.

The OpenCyc Team has missed its estimate of an August 31 delivery. The new estimate appears below as a list of tasks and milestones.

OpenCyc 1.0 will incorporate more capabilities in the first release than originally planned, including:

- Some natural language parsing/generation capabilities

- More support for moving knowledge among KBs.

- An expanded API that will include the ability to define some server-side scripts. A considerable portion of the SubL language will be included.... read more

Posted by John De Oliveira 2001-09-08

OpenCyc CVS activity starting

You can view java source files which define OpenCyc objects, and the constraint solver portion of the inference engine under development. Look for the Browse CVS Repository link on the CVS menu item.

These classes will have a supporting package which handles the OpenCyc server connection.

The test case for the constraint solver is the well known Zebra Puzzle, with one variation described at

Posted by Stephen L. Reed 2001-07-23

Cycorp Founder on NPR Friday

Doug Lenat, Founder and President of Cycorp, will discuss OpenCyc and artificial intelligence this Friday, June 29, on "Talk of the Nation: Science Friday," a weekly science/technology news talk program, broadcast on about 150 NPR affiliates nationwide.

The interview will air live from 2-3pm Eastern, 1-2pm Central and 11am-12pm Pacific. If your local NPR affiliate does not broadcast "Science Friday," you may be able to listen to the show over the internet. streams their live productions, as do some affiliate stations.

Posted by John De Oliveira 2001-06-28

Cyc public ontology released in DAML format

The OpenCyc Upper Ontology is now available in DAML XML format. The Darpa Agent Markup Language is described at Cyc's content is located at It consists of approximately 3,000 classes and binary properties describing high level concepts common to most subject domains. The associated rules, remaining relationships, knowledge-entry tools, sample code, and executable inference engine are planned for release when ready. Please note that this DAML contribution is a restatement of the previously released Cyc Upper Ontology and that the OpenCyc ontology will contain additional content and refinement of included comments.

Posted by Stephen L. Reed 2001-06-27

LA Times article on OpenCyc

LA Times staff writer Michael Hiltzik writes about Cyc artificial intelligence technology, and the OpenCyc project at:

Posted by Stephen L. Reed 2001-06-22

OpenCyc XML schema (CycML) passes the W3C validator

OpenCyc is the open source version of the Cyc(r) knowledge base (artificial intelligence).

Our new XML schema for knowledge serialization has passed the W3C XML schema validator at

Developers can use CycML to exchange knowledge with one another, and CycML will also allow the KB contents to be imported and exported for archiving. The schema definition allows validating XML parsers to check the compliance of CycML with our published schema, regarding the nesting of the defined elements and their attributes. The OpenCyc inference engine ensures that imported CycML assertions are well formed according to the semantic constraints of the contained relationships and concept types.... read more

Posted by Stephen L. Reed 2001-05-29

OpenCyc to include WordNet 1.6

Today OpenCyc received permission from Princeton to include WordNet 1.6 as a datastructure browseable from within the OpenCyc tools. WordNet is a mature lexical reference system that is related to the Cyc knowledge base by associating WordNet word senses to Cyc concepts.

More information on WordNet is available at: And an online WordNet lookup is available at:

Posted by Stephen L. Reed 2001-05-23

Announcing OpenCyc

Posted by Stephen L. Reed 2001-05-15