OpenLogos Machine Translation

  1. OpenLogos Machine Translation
    1. What it is
    2. The OpenLogos License
    3. Availability of OpenLogos Source Code
      1. OpenLogos on Sourceforge
      2. Installation
      3. OpenLogos for Windows
      4. Contact on the OpenLogos Linux port:
    4. Community
    5. Publications and Applications related to OpenLogos

What it is

The LOGOS Machine translation system is one of the largest and most powerful among the commercial machine translation systems. Various text documents in different formats can be submitted to the system and within a short amount of time are translated into different target languages. The result, a raw translation, is already of high language quality. But if required, the result can be post-edited by a human translator. The user saves a significant amount of time and costs especially since the use of different document filters maintain the format of the original document to a high degree.

Currently German and English are the source languages available. The target languages for English include the major European languages (such as French, Italian, Spanish and Portuguese).

The system "can learn" in the sense that a trained user quickly is able to maintain terminology and dictionaries and can also establish his own user dictionary. This is important if the text to be translated belongs to a subject area with specific terminology. The system already has a complex hierarchical system of specialized dictionaries easily accessible for the user. Therefore, from its approach, the LOGOS engine is a "universal problem solving machine" which can process any text in any subject area. "Fine-tuning" or "specialization" is accomplished with the appropriate terminology work.

The LOGOS system had been developed over 30 years to its present form. It requires enormous efforts and resources to develop such a system and adapt it to new uses.

The open source version of LOGOS is available under the name OpenLogos. The article B. Scott: The Logos Model: An Historical Perspective. In: Machine Translation 18 (2003), pp. 1-72 presents an excellent overview of the Logos approach to machine translation.

Bud Scott, one of the founders of Logos, also created a website with more background information and documents about the Logos system at .

The OpenLogos License

OpenLogos has two licensing options.  From a licensing perspective, we have two different products depending on usage and distribution, though technically they have the same source code. These licensing options include:

These conditions pertain to the code as well as to data. Details about the licenses are available in:

Further information can be obtained from Group Business Software AG, Hospitalstraße 6, D-99817 Eisenach, Germany.

Availability of OpenLogos Source Code

The commercial LOGOS system from Group Business Software AG had been developed exclusively for the Microsoft-Windows operating system and is based on other commercial products, such as an Oracle database. So its code depends to some extent on non-open source software such as Windows specific libraries and APIs and other modules that cannot be used freely. The code base consists mainly of C++-code with some packages in C and Fortran. Besides embedded SQL-code for interacting with the database, the database itself contains product specific SQL procedures and triggers.

Therefore, the Language Technology Lab of DFKI started in 2005 to prepare an initial version of the Logos system which is truly open source in employing only open source components. This initial port involves among other steps:

In addition, the major development and customization tools for the Logos translation system were ported and adapted to the open source version of Logos.

OpenLogos on Sourceforge

In September 2010, OpenLogos became the OpenLogos-MT project on  Sourceforge, thanks to an initiative of Michael Roberts. The initial setup consisted of the 1.0.3 release of  OpenLogos that had been provided here. This setup on Sourceforge offers other developers the opportunity to contribute to the project and the further maintenace and development of the system. Current releases for the Linux platform (32-bit) and PostgreSQL as database are available from the Sourceforge site at The Sourceforge site also provides access to the SVN repositories. The release consists of several components


Basic installation and usage instructions for the runtime system and tools are contained in the source archives. Excellent and detailed installation instructions for various Linux versions and distributions are available from the Sourceforge OpenLogos Wiki at

If the system requirements of OpenLogos are difficult to match in a specific environment, one should consider the use of a dedicated virtual machine for the OpenLogos installation. This approach has some advantages: the OpenLogos installation and environment are independent of the host environment and OpenLogos even can be used on other platforms, e.g. a Windows host. An image of a virtual OpenLogos machine for VirtualBox based on Ubuntu-5.10 has been made available at

OpenLogos for Windows

An MS-Windows version of OpenLogos  based on MinGW was started by Norman Reid. This version has not yet been fully integrated with the Linux version due to slightly different build requirements. The Windows version based on the OpenLogos-1.0.3 release therefore still can be obtained here: A binary release of his OpenLogos for Windows is available in the archive. The modified sources for the Windows version are available as Eclipse workspace in Eclipse (with CDT and MinGW) is required for building this Windows version (see Norman's INSTALL.txt file for details). Any issues with these releases should be addressed via the OpenLogos mailing list.

Contact on the OpenLogos Linux port:

Dr. Walter Kasper
Language Technology  Lab
Stuhlsatzenhausweg 3
D-66117 Saarbrücken
Phone: +49-681-3025300


Publications and Applications related to OpenLogos

Data Protection   Legal Notice
Last change:  04.12.2012