Please Note: Portable as in portableapps.com, not in the traditional sense of a language that can be used on multiple architectures or operating systems. Whoeve
Tclkit is a single-file, self-contained Tcl/Tk system. The mac version I have is about 3.8 megs. You can get a version for just about any modern OS. I carry around a thumb drive that has mac, windows and linux binaries so I can run my scripts on any platform. No install is required, just copy one file wherever you want.
The only thing it's missing from your original spec is MS SQL Server / ODBC support out of the box. I know people use tcl for that but I think you'll have to add an extra library or something. See the Tcl'ers wiki entry on MS SQL Server for more information.