OpenLogos
Machine Translation
- OpenLogos
Machine Translation
- What
it is
- The
OpenLogos License
- Availability
of
OpenLogos Source Code
- OpenLogos on Sourceforge
- Installation
- OpenLogos for Windows
- Contact
on the
OpenLogos Linux port:
- Community
- 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 http://logossystemarchives.homestead.com/
.
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:
- The Commercial License, which allows you to
provide
commercial
software licenses to your customers or distribute Logos MT based
applications or to use OpenLogos for commercial purposes.
This is for organizations that do not want to release the source code
for their applications as open source / free software; in other words,
they do not want to comply with the GNU General Public License (GPL).
- For those developing open source applications,
the Open
Source License allows you to use the software at no charge under the
condition that if you use OpenLogos in an application you
redistribute, the complete source code for your application must be
available and freely redistributable under reasonable conditions.
Group Business
Software AG, the owners of Logos, bases its interpretation
of the GPL on the Free Software
Foundation's Frequently Asked Questions.
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:
- Use of open source development tools and
compilers, such as
GCC.
- Replacement of non-open code and libraries.
- Use open source databases instead of a
commercial database.
This
includes a migration of the database content containing all language
specific resources to an open source DB, such as PostgreSQL
- Use of open standards instead of vendor specific protocols.
- As a proof of concept for the software migration, Linux was
used
as target platform for the first OpenSource release of Logos.
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 http://sourceforge.net/projects/openlogos-mt/files/). The Sourceforge site also provides access to the SVN repositories. The release consists of several components
- Database as PostgreSQL binary dump
- Source Code for the runtime system
- Source Code for OpenLogos Tools: Installations instructions are contained in the file INSTALL.tools.
The tools consist of
- LogosTermBuilder
for adapting and extending the translation dictionaries
- LogosTransCenter,
a graphical front-end for translating text files.
- LogosAdmin
for user administration
Installation
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 http://sourceforge.net/apps/mediawiki/openlogos-mt/index.php?title=Main_Page.
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 http://vikitraduko.saluton.dk/openlogos/.
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 OpenLogos_Windows.zip
archive. The modified sources for the Windows version are available as Eclipse workspace in OpenLogos_Windows_SRC.zip. 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
DFKI
GmbH
Stuhlsatzenhausweg 3
D-66117 Saarbrücken
Phone:
+49-681-3025300
Email:
kasper@dfki.de
Community
Publications
and Applications related to OpenLogos
- B. Scott & A. Barreiro: "OpenLogos
MT and the SAL
representation language". In Proceedings of the First
International
Workshop on Free/Open-Source Rule-Based Machine Translation / Edited by
Juan Antonio Pérez-Ortiz, Felipe Sánchez-Martínez, Francis M. Tyers.
Alicante, Spain: Universidad de Alicante. Departamento de Lenguajes y
Sistemas Informáticos. 2-3 November 2009, pp. 19-26
- Wikipedia: OpenLogos
- Anabela
Barreiro used the OpenLogos translation lexica to build a set
of Portuguese-English linguistic resources which are applied to
authoring aids and machine translation. Port4NooJ resources are
described here
and in the article:
The script used for extracting the dictionary
data from the database is available here. - A.
Barreiro, B. Scott, W. Kasper and Bernd Kiefer: OpenLogos:
Rule-Based Machine Translation: Philosophy, Model, Resources and
Customization. In: Machine Translation 25, 2011, pp. 107-126
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Last change: 04.12.2012