BISmark (Broadband Internet Service Benchmark) is a deployment of home routers running custom software, and backend infrastructure to manage experiments and collect measurements. The project began in 2010 as an attempt to better understand the characteristics of broadband access networks. We have since deployed BISmark routers in hundreds of home networks in about thirty countries. BISmark is currently used and shared by researchers at nine institutions, including commercial Internet service providers, and has enabled studies of access link performance, network connectivity, Web page load times, and user behavior and activity. Research using BISmark and its data has informed both technical and policy research. This paper describes and revisits design choices we made during the platform’s evolution and lessons we have learned from the deployment effort thus far. We also explain how BISmark enables experimentation, and our efforts to make it available to the networking community. We encourage researchers to contact us if they are interested in running experiments on BISmark.