Besides the "local" grid functionality it is possible to jump to regions on different OpenSim servers (such as OSGrid, Metropolis, Franco Grid CyberLandia, Standalone Regions etc.) via gateways or direct Teleporting (HyperJump). All this hypergrid enabled grid servers and standalone servers are building the "Hypergrid".
While teleporting in a remote Grid a Hyper Jump will be performed, which teleport you into the remote grid, without logging out from the Metropolis grid. To return to the Metropolis grid just press "CTRL-shift-h" on the keyboard. Attention: This will only work, if a home address is specified.
After the teleporting you may get around in the remote grid and you can fly there from region to region. Further teleporting is also possible. When calling the worlds card in the remote grid, you will see all regions from this remote grid. It is also possible, to teleport again from this remote grid to another remote grid.
Due to a restriction in the software the coordinates of the calling region and the actual coordinates of the called region should differ not more than 4096 coordinate points on each axis. If there is a higher difference in the coordinates, the prims and the terrain of the region will not show up correctly (everything is gray). Furthermore, no avatars (including own avatar) will not show up. Only when flying to another region of this grid or teleporting there, the assets and the avatars will be shown again.