Cooperative integrated sensing and communication (ISAC), an advanced version of ISAC, is becoming an inevitable paradigm in sixth-generation mobile information networks. Based on the foundation of large-scale deployed mobile networks, cooperative ISAC holds promise to realize ubiquitous sensing, thus becoming a significant step in promoting the transformation from connected things to connected intelligence. In this paper, we depict a sweeping panorama of cooperative ISAC, including the concept, key technologies, a performance evaluation framework, and field trials. We start by introducing the application scenarios of cooperative ISAC, which are the motivation for its commercialization. Next, from the perspective of technical development, we trace the evolution of cooperative ISAC, noting that cooperation within sensing and communication is an objective trend. We reveal the four core features of cooperative ISAC—denoted herein as network-enabled, integration, cooperation, and everything—and provide a general system model. Regarding key technologies, we introduce our contributions to antenna array design, cooperative clustering, synchronization, and data fusion, as well as interference management and networking. We also propose an evaluation framework and define several key performance indicators for cooperative ISAC. Through system-level simulations and field trials, we show the practical application feasibility of cooperative ISAC. Finally, we provide guidance on future research directions in cooperative ISAC.