Hi all, I'm looking for examples of tools which take multiple input files (one or more, determined at run time) and produce multiple output files (one for each input file). Any specific suggestions? I have a number of sequence filtering/renaming tools where this might be useful - in some cases taking multiple input files and producing a single output is fine, but in general I'd like to know how to preserve a one to one mapping from input files to output files. I realise this may overlap slightly with the work John is doing on dataset collections, but for now I'd like to target the current Galaxy feature set. In some of the simpler cases, if I have N input datasets and want N output files, I can just run the tool N times . This means more steps in the Galaxy GUI, but it isn't very complicated. However, for the current problem I need access to all the inputs at once for setting overall data derived parameters. Regards, Peter