On the internet information is free, but still locked down in relational database formats of CMSes like Drupal or WordPress. Exporting and importing content can be a chore, but agreeing on a proven format will help content migration projects.
WordPress Extended RSS is an extension to the RSS format and could be a universal language for content migrations. It is widely deployed in the WordPress world and offers enough structure for migrating common content structures like news articles and content pages.
The next time you are doing migrations, consider exporting to WXR first and importing that. Standardising like this will help you the next time around.