Multi-user (MU) - MIMO and OFDMA - is the next revolution in WiFi. Many experimental platforms today can support the exploration of physical layer aspects of MU but cannot run real-time experiments integrated into end-to-end network systems. However, recent work has shown that real network traffic regimes can be equally important to the MU performance of a WLAN. In this thesis we present PERFORM, a novel experimental platform for implementation and evaluation of WLAN MAC policies. This platform is the first end-to-end integrated system that carries real-time network traffic and, at the same time, allows for the flexible prototyping and evaluation of advanced WLAN MAC policies, including MU-MIMO, OFDMA, triggered uplink access, buffer status report, and data-driven policies. We present the platform validation experiments and also show the application of PERFORM in two uplink MU-MIMO experiments to showcase its capabilities and the new research that it enables.