R is a programming language designed for statistics.
R Sparql allows you to run SPARQL Queries inside R and store it as a R data frame. The main objective is to allow the integration of Ontologies with Statistics.
Easy RDF and SPARQL for LAMP systems
ARC is a flexible RDF system for semantic web and PHP practitioners.
It's free, open-source, easy to use, and runs in most web server environments.
CubicWeb is a semantic web application framework, licensed under the LGPL, that empowers developers to efficiently build web applications by reusing components (called cubes) and following the well known object-oriented design principles.
Its main features are:
an engine driven by the explicit data model of the application ,
a query language named RQL similar to W3C's SPARQL ,
The Silk framework is a tool for discovering relationships between data items within different Linked Data sources.
Data publishers can use Silk to set RDF links from their data sources to other data sources on the Web.