  The computation power of supercomputers grows faster than the bandwidth of
their storage and network. Especially applications using hardware accelerators
like Nvidia GPUs cannot save enough data to be analyzed in a later step. There
is a high risk of loosing important scientific information. We introduce the in
situ template library ISAAC which enables arbitrary applications like
scientific simulations to live visualize their data without the need of deep
copy operations or data transformation using the very same compute node and
hardware accelerator the data is already residing on. Arbitrary meta data can
be added to the renderings and user defined steering commands can be
asynchronously sent back to the running application. Using an aggregating
server, ISAAC streams the interactive visualization video and enables user to
access their applications from everywhere.
