Hi everyone! We have something of a problem in that we need a way to join the virtual filesystem locations that we stage files to/from in DataStaging to the places referred to in various places in PosixApplication (especially Argument and Environment, though this also applies to Input, Output and Error; possibly WorkingDirectory too). The problem is that we want to virtualize the location within the real target filesystem(s) that the files are located in, but we do not have any standard substitution scheme; so far, we've only got the ability to specify literal strings which gives either absolute locations (non-portable) or locations that are relative to the working directory (great for the simple cases, but awful for anything complex). In DRMAA, this problem is solved by allowing magical tokens to be put at the start of applicable parameters and defining a substitution scheme for those magical parameters. (This is also the UNICORE approach). That works, but I use the term "magical" with good reason; the values are not easily manipulable with XML processing tools. The other basic alternative, processing with XSLT on the way in, has the problem in that it tends to end up binding things to specific locations far too soon. What I think we need is a way to say that a certain term is to be made relative to a particular virtual filesystem root. As far as I'm concerned, the easiest way of doing this is to put optional attributes on the elements needing this treatment (listed above) that say that the element value needs to be interpreted as being relative to the root of the virtual filesystem named in the attribute, with an absent attribute indicating that the attribute value is to be used literally. Alternatively, we could put a complex type inside the element, but that's much messier IMO. I suggest that the attribute should be called jsdl:filesystem (or rather, whatever we use in DataStaging but I don't remember for sure right now) and we might use it like this fragment: <jsdl:Application> <jsdl:ApplicationName> Gaussian </jsdl:ApplicationName> <jsdl-exec:POSIXApplication> <jsdl-exec:Input jsdl:filesystem="HOME"> input.txt </jsdl-exec:Input> <jsdl-exec:StackSpaceLimit> 8388608 </jsdl-exec:StackSpaceLimit> </jsdl-exec:POSIXApplication> </jsdl:Application> We'd need to decide what predefined virtual filesystems to support, of course. Or have we done that already? :^) Donal.