The Open Semantic Framework (OSF) is a generally RESTful middleware API layer that provides the bridge between existing content, structure and schemas, legacy content management systems and RDF data stores. The OSF Web Services is the set of OSF web services that are used to manage all the content indexed in OSF.
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OSF is a platform-independent Web services framework for accessing and exposing structured RDF (Resource Description Framework) data. Its central organizing perspective is that of the dataset. These datasets contain instance records, with the structural relationships amongst the data and their attributes and concepts defined via ontologies (schema with accompanying vocabularies).

The OSF middleware framework is generally RESTful in design and is based on HTTP and Web protocols and open standards. The initial OSF framework comes packaged with a baseline set of more than 20 Web services in CRUD, browse, search, tagging, ontology management, and export and import. All Web services are exposed via APIs and SPARQL endpoints. Each request to an individual Web service returns an HTTP status and optionally a document of resultsets. Each results document can be serialized in many ways, and may be expressed as either RDF, pure XML, JSON, or different flavors of irON.

In initial release, OSF has direct interfaces to the Virtuoso RDF triple store (via ODBC, and later HTTP) and the Solr faceted, full-text search engine(via HTTP). However, OSF has been designed to be fully platform-independent. Support for additional datastores and engines are planned. The design also allows other specialized systems to be included, such as analysis or advanced inference engines.

The framework is open source (Apache 2 license) and designed for extensibility. OSF and its extensions and enhancements are distributed and documented on the Open Semantic Framework Web site.

You can read more about OSF here


OSF is fully documented on the Techwiki. You can easily access all the documentation pages related to it by checking this category section.


The general OSF architecture is described in this document page. It also explains the echosystem in which it lives (and its related to other parts of the OSF (Open Semantic Framework) like OSF for Drupal.

Installing OSF

Get started quickly with OSF by using the Open Semantic Framework Installer

Additionally you can find debugging tips and support on the Mailing List

Upgrading OSF

An existing OSF instance can easily be upgrader using the OSF-Installer.

Note: the version of the OSF instance that should be minimally installed is version 3.0.0. If you have an older version than that, then you will have to manually upgrade your version to the version 3.0.0 and then you will have to run the OSF-Installer OSF upgrader script.

OSF Web Services

Here is a complete list of all the web service endpoints currently available in OSF:

How to Use Web Services Endpoint

The easiest way to get started is to use the OSF Web Services PHP API to create and send queries to any OSF web service endpoint.

Administer an OSF Instance

Many command line tools exists to help system administrators to administer a OSF instance. The tools are:

Testing an OSF Instance

An integration tests suites that includes more than 700 tests and 4000 assertions as been developed to test all the features of a running OSF instance:

These tests can be run at any time to make sure that the instance is fully operational. It is normally used by the OSF Installer to make sure that an instance is fully operational after OSF is installed, or after it got upgraded.


Developers and commiters to the Git repository should comply to the coding standards. An outline of the coding style is available in the Coding Standard folder. Additional requirements are listed in the README.mediawiki file in that folder. Finally, coding style is enforced b the PolyStyle code formatter application available here:

Auto-loading of Classes

OSF does comply with the [PSR-0]( for auto-loading the classes of the framework. The SplClassLoader class that has been developed by the same group can be used as the classes auto-loader.