In order to consolidate and decode some of the information you need to sift through when learning about rich snippets, we've created this visual guide to walk through the basics, fundamental types, implementation, and benefits of utilizing them.   

Microformats, RDFa and microdata all enable consumers to extract data from HTML pages. This data may be embedded within enhanced search engine results, exposed to users through browser extensions, aggregated across websites or used by scripts running within those HTML pages.

This guide aims to help publishers and consumers of HTML data use it well. With several syntaxes and vocabularies to choose from, it provides guidance about how to decide which meets the publisher's or consumer's needs. It discusses when it is necessary to mix syntaxes and vocabularies and how to publish and consume data that uses multiple formats. It describes how to create vocabularies that can be used in multiple syntaxes and general best practices about the publication and consumption of HTML data.

Web Data Commons will extract all Microformat, Microdata and RDFa data that is contained in the Common Crawl corpus and will provide the extracted data for free download in the form of RDF-quads as well as CSV-tables for common entity types (e.g. product, organization, location, ...).

This post attempts to clarify those technical issues by providing an easy-to-read list of similarities and differences between RDFa, Microdata and Microformats. A simple table summarizing all features across each structured data syntax is listed below. Each feature is linked to a brief explanation of the feature toward the bottom of the page.

What Google does with embedded metadata.

CSS is an external file that specifies how your document should look; RDF-EASE is an external file that specifies what your document means.

hkit is a simple PHP5 tool for extracting common microformats from a page.

Easily transform your microformatted content to nice, clean, easily digestible, XML, JSON or JSON-P. You can also easily set filters to only receive particular formats.