In this presentation, I illustrate, and discuss initial results from a quantitative analysis of the performance of WPS servers. To do so, two test scenarios were used to measure response time, response size, throughput, and failure rate of five WPS servers including 52¡North, Deegree, GeoServer, PyWPS, and Zoo. I also assess each WPS server in terms of qualitative metrics such as software architecture, perceived ease of use, flexibility of deployment, and quality of documentation. A case study addressing accessibility assessment is used to evaluate the relative advantages and disadvantages of each implementation, and point to challenges experienced while working with these WPS servers.