I just discovered a scant reference to this on the ToolSyntax page, and tracked it down to something that looks like it was introduced around 2011: a "LibraryDatasetToolParameter" http://bitbucket.org/galaxy/galaxy-central/changeset/8553b02ce9ee/ changeset: 8553b02ce9ee user: kanwei date: 2011-07-19 03:56:23 summary: Tools: Add new LibraryDataset tool parameter to expose LDDAs to tools. Use trackster's modal popup interface for item selection. Add new InputWrapper that exposes LDDA templates as well. Now I can't quite fathom the syntax around this but it appears to be broken - python error displayed: TypeError: get_initial_value() got an unexpected keyword argument 'history' Which is because in the galaxy code the def get_initial_value( self, trans, context ) function is missing a "history=None" parameter like other types have?! But is this input type essentially discontinued (no other refs to it on the web) or is it supposed to be operational? I was hoping for a tool input that would list a particular libraries datasets, so that I could obtain their file paths for use in my tool. <param name="test" type="library_data" label="test" help="test help"/> <options library="Reference Bins"> </param> Regards, Damion Hsiao lab, BC Public Health Microbiology & Reference Laboratory, BC Centre for Disease Control 655 West 12th Avenue, Vancouver, British Columbia, V5Z 4R4 Canada