No platform is an island.

In Scalar, every node — whether page, media, path, tag, annotation or beyond — has the ability to connect with other nodes in a variety of ways. This “flattened hierarchy” is a result of Scalar’s implementation of Semantic Web principles with a helping hand from third party applications and protocols. The third party apps provide database, interactive, and other common services that assist in the creation of Scalar features. In addition, protocols such as RDF provide a standards-based way for Scalar to communicate with itself and outside systems.

Scalar’s source code is released under the Educational Community License v2.0.

Third Party Applications and Protocols

Server-side

CodeIgniter CodeIgniter provides Scalar a Model-View-Controller environment (layered over PHP) and a number of helpful libraries to assist in the speedy development of the software.	ARC2 Originally created by Benjamin Nowack and now on GitHub, ARC2 is a semantic web database layered over MySQL that facilitates the storage of extensible metadata imported or entered into a Scalar book.	PHP The programming engine behind most of the web, we chose PHP over similar languages (such as Ruby) because of its wide implementation on institutional and commercial servers.
MySQL We chose MySQL primarily due to ARC2’s dependance on the database. Scalar implements a hybrid set of tables: key page and version info is kept in relational tables, while extensible metadata is kept in semantic ARC2.	XSLT Scalar connects to partner archives, and their content can be imported directly into your project. XSLT is the technology that converts domain-specific information from the archives into RDF, Scalar’s core language.

Client-side

jQuery Given the complexity of Scalar’s built-in visualizations, media players, and menus, jQuery lets us focus on user experience rather than browser support. Note that we use freely available jQuery plugins not listed here.

D3 Growing in popularity, D3 is a JavaScript library that drives the visualizations built into each Scalar book.

RDF We looked for a communications standard that could pass page information from server to client and back — and with outside systems — while maintaining rich metadata and relationships. RDF is the W3C Semantic Web standard and was designed for this purpose.