I'd like to do a very broad search to find a cheap airfare between South America and Asia. I have a list of possible origins and possible destinations (like a matrix). Is there such a flight fare search engine that could fill out all matrix cells for a specific date or range?Origin/Destination  Tokyo   Singapore Bangkok   Hong KongLima                Santiago                Quito               Buenos AiresEditIs there a free public API for flight fares out there? It wouldn't be too hard to program.
Broad flight fare search
webapp rec;search;travel
ITA Software, Kayak APIHave you taken a look at ITA software's Matrix2?  Again, it's not perfect, but it lets you define a 300-mile radius for departure and destination airports.  It also allows for flexibility in the date or display of a lowest fare calendar.They don't have a public API, but they're the ones who power Kayak and many of the other flight search engines.  They were recently acquired by Google.Kayak does have an API you can use to populate your matrix.  In fact, this mashup looks like it does part of what you want.