The difference between SPARQL 1.1 and MQL (the propreitary Freebase language) is like the difference between chess and checkers.

In SPARQL you can write queries that involve any graph relationships that come into your head. You can take the UNION of multiple graph patterns. With SPARQL you can also get back 200,000 or more results.

With MQL you quickly run into the wall when you find that you can't write the query you want (you need to write 10,000 queries instead of one) or that the query you want to run times out, or that it only lets you get back a limited number of answers.

It's also possible to do batch processing with :BaseKB Pro with extreme efficiency. We did a calculation that would have taken 100 years on the biggest machine in the AMZN cloud in SPARQL in just 24 hours on a mac book pro with an optimized pipeline.

How about the Freebase quad dump? Can't I just import that into virtuoso and do the same sparql queries?

You'll need to process that file into something that your DB can consume. If all you need are minor syntax tweaks, you can stream straight through.

More likely, you'll need to rebuild the dump to be more than quads ordered by arbitrarily assigned unique id, and with nearly 600 million quads, it's not completely trivial to do, might involve temporary index files, etc.

Still, it's doable.

(also see: http://code.google.com/p/freebase-quad-rdfize/ )

The Freebase "quad" dump is not in RDF format, and so cannot be imported into any standard RDF store.

The Freebase API is a hosted service. MQL is designed for fast HTTP queries that power interactive webapps.

SPARQL is harder to learn and set up, but allows for more complicated queries that might require offline processing.

(I designed the first version of MQL)