The technology needed to implement the grid includes new protocols, services, and APIs for secure resource access, resource management, fault detection, and communication. Moreover, one introduces application concepts such as virtual data, smart instruments, collaborative design spaces, and meta-computations. All over the world national and international grid initiatives have been funded. In high-energy physics recently the first phase of the LHC Computing Grid Project has been set up. Its role is to prepare, coordinate, and manage the international infrastructure needed to share and handle on the grid the unprecedented amount of data (several peta-bytes per year) that the LHC experiments will generate starting around 2007. Architectures and resources have to be defined to fulfil the needs of the various participating scientific and engineering communities of over 6000 physicists and engineers coming from more than fifty different countries in Europe, the Americas, Asia and elsewhere.