Finding affordable flights has become a sport widely played on the field called the internet. Long gone are the days when most people turned to travel agents or had to call the various airlines directly to find cheap travel deals. Nowadays by going online, many folks find inexpensive airfares themselves.

Looking for cheap airfare online? Try ITA Matrix

Technology has done much to disrupt the airfare search business. We told you how Google Flights' streamlined interface has created parity when comparing air travel. But the software behind that site is the real secret sauce.

It originates from a company called ITA Matrix, formed by MIT researchers in 1996. The Cambridge, Massachusetts, firm specialized in airline metadata, which offers expanded functionalities, including cost-per-mile analysis and much more. The magic behind ITA Matrix’s search capabilities is its QPX, or executable query technology.

ITA's software is so good that several big-name travel players like Kayak.com, Cheaptickets.com, Orbitz and airlines such as American, United and US Airways used their services, paired, of course, with payment options. (Priceline stayed with Travelport software. Travelocity opted for Sabre.)

Seeing huge opportunity in travel search, Google bought ITA in 2010. Late last year, Google announced that it was shutting down an ITA-related project geared toward third-party developers. QPX Express API's last day will be April 10, 2018.

A larger related business, QPX Enterprise, which powers many of the travel sites mentioned above, will remain open. Among the recent cuts was ITA Software’s mobile app, OnTheFly, which was retired in December.

But take heart, consumers, you can continue to enjoy the ITA Matrix site at matrix.itasoftware.com, which as far as we know, isn't going anywhere. The legacy site remains a robust and fully customizable airfare search site for travelers looking for the best prices, especially on last-minute fares.

Here are some of the best features included in the ITA Matrix

Advanced route-coding capability: One of the groundbreaking things about ITA software is that you can use codes to do things like avoid certain airports, limit the duration of an itinerary or exclude red-eye flights or flights with overnight stops. In Matrix, click the Advanced routing codes link to see the routing code fields, and then enter your codes in the fields stated Enter outbound/return routing codes.

Interactive Calendar: You can also explore date ranges and lowest fares by utilizing the calendar view. To see it, click "See calendar of lowest fares" instead of "exact dates" when searching.

Multi-city flights: No other site offers the capability to search for as many as six flights at one time. If you need to add more than two cities, simply click on "add another flight."

Color-coded time bars: If you tend to get overwhelmed by text-based searches, try the color-coded timeline chart, which highlight stops, schedules, layovers and other options through filtered hues.

Flexible dates: The ability to see how cheap an airfare would be a day or two later or earlier has been integrated into Google Flights, but it was originally a Matrix innovation and remains a ready resource here.

One thing ‘The Matrix’ can’t do

As you can see, the functionality of ITA Matrix sets it apart. About the only thing the software can't do is show you Southwest Airlines flight prices, which only available through the airline's web site.