SemanticMarkupInHtml

Several formats exist for adding semantics to web pages: microdata, RDFa and microformats. This page aims at giving a fair comparison between these formats, acknowledging their strengths and weaknesses. The goal of this comparison is to allow web developers to choose what format might work best for their use case.

Microformats were the first widely used approach to semantic markup allowing web developers to add structured data to their HTML pages. It emerged from a grassroots movement. Examples of microformats are hCalendar, hCard, hReview, etc.

RDFa is a W3C Recommendation that adds a set of attribute-level extensions to XHTML for embedding rich metadata within Web documents.

Microdata is a more recent syntax developed as part of the HTML5 specification.

@TODO: turn this into a table?

• verbosity: RDFa tends to be less verbose as it allows to chain HTML elements and use several attributes in the same tag.
• maturity: RDFa was started in 2004, includes many libraries in JavaScript, Perl,
• RDFa supports datatyping which MD lacks http://www.jenitennison.com/blog/node/103
• RDFa supports XML literals which MD lacks http://www.jenitennison.com/blog/node/103