Microsoft has been ranked at the top of the worldwide unified communications (UC) vendors list, followed by Cisco Systems and IBM claiming the second and third spots, respectively, according to the Vendor Matrix released by ABI Research.

Senior analyst Subha Rama said Microsoft has shown the strongest growth among UC vendors, leveraging its position as a leader in desktop applications.

"It has, over the years, integrated multiple solutions in its portfolio to offer a compelling software-based UC solution in Lync," Rama said.

"Microsoft also has the widest spectrum of partners for Lync and is expanding this ecosystem rapidly. It has an equally significant play both on the premises and in the cloud."

Practice director Dan Shey said Cisco scores very high for the way it has evolved its UC channel partner ecosystem: all leading system integrators view Cisco as one of the top two key vendors in this space.

"IBM was among the first to bring a high degree of credibility to the integration of social computing tools with UC platforms," Shey said.

For this particular matrix, vendors are assessed on the important parameters of "innovation" and "implementation" across several criteria unique to each vendor matrix.