ZetaWorlds uses a custom built CDN to serve assets, this makes loading creations much faster no matter where in the world you host your region or what foreign grid you are in retreiving the item from your home grid.
ZetaWorlds builds almost everything we use ontop of opensim ourselves. We work with other grids to help make even cooler features. Be sure to check out our credits page to learn more about who we helps us out.
ZetaWorlds has built the grid to be load balanced for heavy loads, we run multiple instaces of grid services behind load balancers that assist with loads. Using our own custom asset service to handle heavy asset load.