Grid computing can be characterized as a distributed infrastructure that joins computing resources of multiple organizations together and enables the effective collaboration among researchers and engineers. Some of the future types of Grid applications will place very high demands on the network, often requiring the speedy delivery of the same data to multiple destinations. The communication in such cases will be only feasible if reliable multicast is used. This paper addresses the use of reliable multicast in Grid computing, identifying potential applications and requirements, and discusses how these requirements are met by protocols being standardized by the Internet Engineering Task Force (IETF). The emphasis of our study is on high-performance computing and communication, and on NORM protocols. The two existing implementations are compared with each other and with standard off-the-shelf TCP. Our findings are valid for applications that require high-speed reliable dissemination of large amounts of data over the Internet, such as RealityGrid, but can benefit other Grid projects too. Unlike previous work, this paper considers the use of reliable multicast in one-to-few Grid scenarios, and provides a practical comparison in the actual network environment to assess the suitability of such protocols.