This project contains a full-stack implementation of a tomographic reconstruction and visualization pipeline. RECAST3D is visualization software for tomographic imaging based on on-demand reconstruction of arbitrary slices, and is built for use in a distributed, real-time, and online reconstruction pipeline. The repository also contains two support libraries, TomoPackets and SliceRecon. The TomoPackets library defines a protocol for sending messages between the different components (scanners, reconstruction nodes, visualization workstations) for real-time tomographic reconstruction and we encourage its use also outside of RECAST3D. SliceRecon contains efficient implementations for reconstructing arbitrarily oriented slices through a 3D volume. It defines servers that are able to communicate to data sources (using TomoPackets) and visualization software (such as, but not exclusively, RECAST3D).