Spynergy is a pure-Tcl toolkit, created by Steve Wahl and Michael Doyle, and included with the BOOK Interactive Web Applications With Tcl/Tk. It provides a set of procedures for distributed processing, URL retrieval, HTML rendering, database management and platform independent file management. It was developed to be compatible with Tcl 7.6 through 8.0, and hasn't been updated since then, but the tools all seem to work fine with current versions.