Anyone writing custom software to query MLS data?

[David Kay]

I'm a computer programmer by trade and I own a few rental properties. I'm always looking for the next deal but I find it time consuming manually crunching numbers that a.) my real estate agent sends over or b.) I find on MLS websites. I'm looking for a way to mass query MLS data via an API and analyze thousands of properties according to my specifications/criteria/strategy.

Does anyone have experience with writing (or using) custom software that does this?