I imagine that the author had in mind other Free relational systems, rather than NoSQL or proprietary. For example, off the top of my head: * Postgres * Apach

I imagine that the author had in mind other Free relational systems, rather than NoSQL or proprietary. For example, off the top of my head: * Postgres * Apache Derby * SQLite All of which I'd prefer to using MySQL in just about any context, and each of which has contexts for which it's overwhelmingly the best choice.