Adobe CEO Shantanu Narayen, Microsoft CEO Satya Nadella and SAP CEO Bill McDermott announce the Open Data Initiative at Microsoft's 2018 Ignite conference in Orlando, Florida.

Legacy tech companies have been scooping up smaller cloud and software providers in massive deals throughout 2018.

The consolidation comes as older enterprise tech companies strive to stay relevant against the juggernaut of Amazon Web Services, as well as Google's well-funded cloud play and a rising crop of nimble venture-backed start-ups.

On Sunday, SAP became the latest to enter the fray, paying $8 billion in cash for survey software company Qualtrics shortly before it planned to go public.

SAP is in good company. Here are some of the other giant deals done by big enterprise players this year:

IBM bought Red Hat for $34 billion

IBM made a $34 billion all-cash purchase of open-source software company Red Hat last month. It was the third-largest U.S. tech merger ever and IBM's largest acquisition.

Red Hat will help boost IBM in the growing market for "hybrid cloud," where companies run critical business software in both their local data centers and in hosted environments from the big cloud providers like Amazon and Microsoft. In particular, Red Hat's version of the open-source Linux operating system runs on many clouds, including those from Google and Microsoft, which will help IBM keep bringing in revenue as companies step into the cloud.

Adobe bought Marketo for $4.75 billion

Adobe bought Marketo, a marketing software company, for $4.75 billion in September. Adobe said it will use Marketo's product for its Adobe Experience Cloud platform for direct-to-consumer marketing.

Cisco bought Duo Security for $2.35 billion

Cisco announced in August that it would buy cybersecurity company Duo Security in a $2.35 billion deal. It was Cisco's second-largest security-related acquisition ever, and will help bolster the company's growing security business.

Broadcom bought CA Technologies for $18.9 billion

Chip-maker Broadcom announced it would buy enterprise software company CA Technologies for $18.9 billion in July. The move came after Broadcom's $117 billion bid for rival Qualcomm was blocked by the Trump administration over security concerns in March. The deal just closed last week.

Microsoft bought GitHub for $7.5 billion

Microsoft bought the software development platform GitHub for $7.5 billion in stock in June.

The acquisition will help Microsoft court developers as it moves beyond Windows and consumer products to promote its cloud and online services offerings. Microsoft has seen its once-dominant Windows unit slip in market share in recent years, spurring a cloud-first reorganization and sending Microsoft looking for alternative ways to attract developers.

Salesforce bought Mulesoft for $6.5 billion

Salesforce acquired software company Mulesoft in a $6.5 billion cash and stock deal in March. Mulesoft makes software that helps company stitch together a variety of cloud services. Salesforce will use Mulesoft's products to help customers sync data across apps located in different places, including various cloud services and on-premises data centers.

Ari Levy and Jordan Novet contributed to this story.

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