tRNAscan-SE was written in the PERL (version 5.0) script language. Input consists of DNA or RNA sequences in FASTA format. tRNA predictions are output in standard tabular or ACeDB format. tRNAscan-SE does no tRNA detection itself, but instead combines the strengths of three independent tRNA prediction programs by negotiating the flow of information between them, performing a limited amount of post-processing, and outputting the results in one of several formats.