Use <b> when you want the text to have a different style without contextual importance, but use <strong> when you want the text to have extra importance from a content or SEO perspective. Use <i> to offset the mood of text, but use <em> to make text emphatic.
RDFa is an extension to HTML5 that helps you markup things like People, Places, Events, Recipes and Reviews. Search Engines and Web Services use this markup to generate better search listings and give you better visibility on the Web, so that people can find your website more easily. http://rdfa.info/
You love Doctrine2 and its explicit way of doing things, but miss i18n from Doctrine1 and Propel? Want to make rich i18n forms or retrieve all your entity translations in one simple query?