Generates simulated single-end or paired-end RNA-Seq reads. RNASeqReadSimulator is a set of scripts that provides users an application to allow experienced users to expand functions. It allows users to randomly assign expression levels of transcripts and generate simulated single-end or paired-end RNA-Seq reads. It is also able to simulate random read errors from sequencing platforms. All scripts are command line driven and allows users to invoke and design more functions.