Mulgara (software)
Encyclopedia
Mulgara is a triplestore
and fork
of the original Kowari project. It is Open Source
, scalable, and transaction-safe. Mulgara instances can be queried via the iTQL query language
and the SPARQL
query language.
In September 2005, Tucana was bought by Northrop Grumman
. In January 2006, Northrop Grumman threatened a Kowari developer with legal action if he released any new version of Kowari. As a consequence, Kowari was forked
in July 2006. It was renamed to Mulgara as Northrop Grumman owned the Kowari trademark. All development on Kowari has stopped and the community moved to Mulgara. The legal cloud surrounding Kowari was eventually resolved , one of the outcomes was the adoption of the Open Software License
3.0. Since 2008 all new code is being licensed with the Apache 2.0 License
.
Since 2006 Mulgara 1.0.0 has been released, significant changes to the transaction architecture was made to support JTA
, SPARQL
support, a Jena
API, and integration with Sesame
has been added. As of February 16, 2010 the latest version is 2.1.7.
(RDF) standard. Metadata may be imported into or exported from Mulgara in RDF or Notation 3
form.
Triplestore
A triplestore is a purpose-built database for the storage and retrieval of Resource Description Framework metadata.Much like a relational database, one stores information in a triplestore and retrieves it via a query language...
and fork
Fork (software development)
In software engineering, a project fork happens when developers take a legal copy of source code from one software package and start independent development on it, creating a distinct piece of software...
of the original Kowari project. It is Open Source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
, scalable, and transaction-safe. Mulgara instances can be queried via the iTQL query language
Query language
Query languages are computer languages used to make queries into databases and information systems.Broadly, query languages can be classified according to whether they are database query languages or information retrieval query languages...
and the SPARQL
SPARQL
SPARQL is an RDF query language; its name is an acronym that stands for SPARQL Protocol and RDF Query Language. It was made a standard by the RDF Data Access Working Group of the World Wide Web Consortium, and considered as one of the key technologies of semantic web...
query language.
History
Kowari was first made available for download in beta form on the 26th of October 2003. In April 2004, Tucana Technologies Inc demonstrated the Tucana Knowledge Server (TKS), a proprietary RDF database relying on Kowari as the basis. A steady number of releases occurred throughout 2004, including version 1.0.5 and 1.1 pre-release. The development of TKS stalled due to difficulties with funding at the end of 2004 , while the development of Kowari continued on .In September 2005, Tucana was bought by Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...
. In January 2006, Northrop Grumman threatened a Kowari developer with legal action if he released any new version of Kowari. As a consequence, Kowari was forked
Fork (software development)
In software engineering, a project fork happens when developers take a legal copy of source code from one software package and start independent development on it, creating a distinct piece of software...
in July 2006. It was renamed to Mulgara as Northrop Grumman owned the Kowari trademark. All development on Kowari has stopped and the community moved to Mulgara. The legal cloud surrounding Kowari was eventually resolved , one of the outcomes was the adoption of the Open Software License
Open Software License
The Open Software License is a software license created by Lawrence Rosen. The Open Source Initiative has certified it as an open source license, but the Debian project judged version 1.1 to be incompatible with the DFSG...
3.0. Since 2008 all new code is being licensed with the Apache 2.0 License
Apache License
The Apache License is a copyfree free software license authored by the Apache Software Foundation . The Apache License requires preservation of the copyright notice and disclaimer....
.
Since 2006 Mulgara 1.0.0 has been released, significant changes to the transaction architecture was made to support JTA
Java Transaction API
The Java Transaction API is one of the Java Enterprise Edition APIs allowing distributed transactions to be done across multiple XA resources in a Java environment. JTA is a specification developed under the Java Community Process as JSR 907...
, SPARQL
SPARQL
SPARQL is an RDF query language; its name is an acronym that stands for SPARQL Protocol and RDF Query Language. It was made a standard by the RDF Data Access Working Group of the World Wide Web Consortium, and considered as one of the key technologies of semantic web...
support, a Jena
Jena (framework)
Jena is an open source Semantic Web framework for Java. It provides an API to extract data from and write to RDF graphs. The graphs are represented as an abstract "model". A model can be sourced with data from files, databases, URLs or a combination of these...
API, and integration with Sesame
Sesame (framework)
Sesame is an open-source framework for querying and analyzing RDF data. It was created, and is still being maintained, by the Dutch software company . It was originally developed as part of the "On-To-Knowledge", a semantic web project that ran from 1999 to 2002. It contains a triplestore.Sesame...
has been added. As of February 16, 2010 the latest version is 2.1.7.
Internals
Mulgara is not based on a relational database due to the large numbers of table joins encountered by relational systems when dealing with metadata. Instead, Mulgara is a completely new database optimized for metadata management. Mulgara models hold metadata in the form of short subject-predicate-object statements, much like the W3C's Resource Description FrameworkResource Description Framework
The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...
(RDF) standard. Metadata may be imported into or exported from Mulgara in RDF or Notation 3
Notation 3
Notation3, or N3 as it is more commonly known, is a shorthand non-XML serialization of Resource Description Framework models, designed with human-readability in mind: N3 is much more compact and readable than XML RDF notation...
form.
See also
- SesameSesame (framework)Sesame is an open-source framework for querying and analyzing RDF data. It was created, and is still being maintained, by the Dutch software company . It was originally developed as part of the "On-To-Knowledge", a semantic web project that ran from 1999 to 2002. It contains a triplestore.Sesame...
- JenaJena (framework)Jena is an open source Semantic Web framework for Java. It provides an API to extract data from and write to RDF graphs. The graphs are represented as an abstract "model". A model can be sourced with data from files, databases, URLs or a combination of these...
- JRDFJRDF (framework)JRDF is an open source RDF framework for Java. It provides an object oriented model of RDF graphs including URIs, Literals and Blank Nodes. It was initially released in 2003 from work on the TKS and Kowari triple stores in order to provide an API that could be used to bridge other APIs such as...
- CubicWebCubicWebCubicWeb is an open source semantic web application framework, licensed under the LGPL. It is written in Python.It has been an open free software project since October 2008, but the project began in 2000 and was initially developed by for internal uses such as intranet, bug tracker and forge...