Is business performance management software the same as business execution software? What are the differences?

They are essentially the same. Solution providers realized, through some fairly compelling research, is that there is significant unrealized value by organizations using BPM solutions.

Historical BPM solution usage has focused on employee performance management. This is a critical component in a BPM initiative. However, the full value of BPM solutions cannot be realized if organizations are not enabled to align organizational objectives with business unit and individual employee goals. Business execution focuses on this upstream need to establish clear objectives and have alignment from with these objectives from each level of the organization.

My sense is that solution providers are seeing a need to re-brand their BPM application suite to emphasize the importance of this goal alignment concept.