For the third straight year, Microsoft Azure ranks just behind Amazon Web Services in the coveted upper-right corner of Gartner’s annual “Magic Quadrant” ranking of Infrastructure as a Service (IaaS) providers, released today.

Both are termed “leaders,” the only two among 10 contenders to win that title in what’s come to be called the “MQ,” a well-respected guide for consumers and a way for vendors to gauge their progress. The quadrant’s X axis reflects completeness of vision, while its Y axis assesses ability to execute.

“The market for cloud IaaS has consolidated significantly around two leading service providers,” Gartner wrote. “The future of other service providers is increasingly uncertain.”

Today’s 47-page report analyzes only IaaS, which Gartner defines to include both public and private cloud offerings. Gartner issues separate Magic Quadrants for other aspects of cloud computing, including storage. (Amazon and Microsoft recently scored first and second, respectively, in that report, too.)

Google ranks a distant third, categorized as “visionary,” while the other seven — CenturyLink, Fujitsu, IBM, NTT Communications, Rackspace, Virtustream and VMware — are clustered in the lower-left corner and labled “niche players.”

The two leaders’ relative positions haven’t shifted at all from last year’s IaaS Magic Quadrant report, though several IaaS providers — including CSS, Dimension Data, Interoute, Joyent and Verizon — have vanished. Last year’s report warned that the IaaS market was in a “state of upheaval.”

Amazon Web Services has a compute capacity “many times the aggregate size of all other providers in the market,” this year’s report said. “It is now a mature provider, yet it remains an agile, innovative thought leader (that) provides the deepest capabilities for governing a large number of users and resources. It has become the ‘safe choice’ in this market.” But “optimal use requires expertise” and possibly consultation, the report cautioned. AWS “is not eager to be the lowest-cost bidder.”

Microsoft Azure, originally a Platform as a Service (PaaS) offering, only expanded into IaaS in April 2013, making it seven years younger than AWS. Its PaaS and IaaS offerings “operate and feel like a unified whole,” the report said. It “has a vision” of features and services that extend to and interoperate with on-premises Microsoft infrastructure. Microsoft has pledged to maintain pricing comparable to that of AWS, and though it “is neither as feature-rich nor as mature as AWS, many organizations can now consider it ‘good enough’ and base their vendor decision on factors other than technical capabilities.” But not all functionality is thoroughly implemented or easy enough to use, and some Microsoft partners lack extensive Azure experience, the report noted.

Third-ranked Google only entered the IaaS market in December 2013, making it the youngest of the three front-runners. It is technologically innovative, especially with big data, analytics, machine learning and batch processing, and should be evaluated “as if it were a specialized cloud platform for projects that play to these strengths,” the report said. Its feature set and services aren’t as broad as the leaders’, and it’s missing some key capabilities such as suitable user management. Google “is still in the rudimentary stages of learning to engage with enterprise and mid-market customers, especially those that are not technology-centric businesses.”

IBM, lower and to the left of CenturyLink, Rackspace and Virtustream, offers IaaS through SoftLayer, which it bought in July 2013. Six months later, it shut down its own SmartCloud Enterprise IaaS offering. SoftLayer has “a long track record as a dedicated hosting provider,” and IBM itself “has a strong brand and existing customer relationships across the globe,” the report said. But “SoftLayer’s feature set hasn’t improved significantly” since IBM bought it, and IBM has changed direction since then, preferring a mixture of PaaS and IaaS known as Bluemix. SoftLayer “is missing many cloud IaaS capabilities desired by mid-market and enterprise customers.”