I'm relatively new to Tcl.  I like its cross-platform compatibility and stringiness, but I love its ability to be glued into other apps.

Tcl projects:
   * GPIB-Tcl http://gpib-tcl.sourceforge.net for controlling IEEE-488 equipment from Tcl.
   * Pets 411 http://pets411.sourceforge.net for creating simple animal rescue databases to export via XSLT to Web sites or to animal-oriented search engines.