The present invention relates generally to non-integrating viral delivery system and methods of using the same. The viral delivery systems includes a viral carrier, a heterologous viral episomal origin of replication, a sequence encoding at least one initiator protein specific for the heterologous viral episomal origin of replication, and at least one gene, shRNA, siRNA, miRNA, or other gene-silencing RNA of interest. In certain embodiments, the disclosed system can be used for gene therapy.