Tech giants like IBM and Google have invested billions internally in A.I. research, but the past few years have also seen a wave of acquisitions, as big companies buy up startups to obtain top talent and new data-crunching science. (Acquisition figures are since 2010. source: CB Insights)

ALPHABET

(14 ACQUISITIONS)

> Google CEO Sundar Pichai has made the case that artificial intelligence is core to the search giant's major businesses. It definitely shows in its acquisitions, including its 2014 purchase for over $600 million of U.K.-based Deep-Mind--whose software is best known for being the first to defeat a human champion at the strategy game Go (above).

APPLE

(13 ACQUISITIONS)

> Apple kicked off its A.I. acquisition spree in 2010 when it bought Siri, whose voice-recognition interface has since become, for many, the embodiment of consumer-facing A.I.

FACEBOOK

(6 ACQUISITIONS)

> The social networking giant is also an A.I. heavyweight, using deep learning to clean up its News Feed (though that's very much a work in progress). Its recent big buys include the 2017 acquisition of Ozlo to improve its messaging app.

AMAZON

(5 ACQUISITIONS)

> It takes a lot of A.I. to fuel both its online retail (matching products to customer preferences) and its cloud-computing business. Amazon also uses A.I. to help screen the produce it ships through its grocery delivery business.

INTEL

(5 ACQUISITIONS)

> Part of Intel's push into A.I. involves researching new computer chip lines, outside of its breadand-butter CPUs that power PCs. Its recent acquisitions are aimed at helping it develop specialized chips for A.I. functionality.

MICROSOFT

(5 ACQUISITIONS)

> As Microsoft shifts its focus from the Windows operating system to cloud computing, it's also investing heavily in A.I.--whether it's data-crunching tech it can sell to customers or its Cortana virtual assistant.

MELTWATER

(5 ACQUISITIONS)

> Marketing and business intelligence firm Meltwater uses A.I. to help customers measure the effectiveness of their advertising and marketing campaigns.

TWITTER

(4 ACQUISITIONS)

> Data-crunching tech working behind the scenes helps Twitter make sure that tweets from your preferred friends, celebrities, and media outlets surface correctly in your feeds.

SALESFORCE

(4 ACQUISITIONS)

> Salesforce uses A.I. to help its software tools better parse emails and recommend sales prospects to its customers.

(For more, see "Unmasking A.I.’s Bias Problem.”)

A version of this article appears in the July 1, 2018 issue of Fortune with the headline "The M&A of A.I.."