License listed as : 'BSD License' on http://sourceforge.net/projects/tcllib , tcllib contains both tcllib and BWidgets.

BWidget ToolKit
Copyright (c) 1998-1999 UNIFIX. 
Copyright (c) 2001-2002 ActiveState Corp. 
 
The following terms apply to all files associated with the software
unless explicitly disclaimed in individual files.
 
The authors hereby grant permission to use, copy, modify, distribute,
and license this software and its documentation for any purpose, provided
that existing copyright notices are retained in all copies and that this
notice is included verbatim in any distributions. No written agreement,
license, or royalty fee is required for any of the authorized uses.
Modifications to this software may be copyrighted by their authors
and need not follow the licensing terms described here, provided that
the new terms are clearly indicated on the first page of each file where
they apply.
 
IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
 
THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE
IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE
NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
MODIFICATIONS.
 
GOVERNMENT USE: If you are acquiring this software on behalf of the
U.S. government, the Government shall have only "Restricted Rights"
in the software and related documentation as defined in the Federal 
Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
are acquiring the software on behalf of the Department of Defense, the
software shall be classified as "Commercial Computer Software" and the
Government shall have only "Restricted Rights" as defined in Clause
252.227-7013 (c) (1) of DFARs.  Notwithstanding the foregoing, the
authors grant the U.S. Government and others acting in its behalf
permission to use and distribute the software in accordance with the
terms specified in this license. 


 BWidget-1.6.0

 arrow.tcl        checked for disclaimer - none
 bitmap.tcl       checked for disclaimer - none
 buttonbox.tcl    checked for disclaimer - none
 button.tcl       checked for disclaimer - none
 color.tcl        checked for disclaimer - none
 combobox.tcl     checked for disclaimer - none
 dialog.tcl       checked for disclaimer - none
 dragsite.tcl     checked for disclaimer - none
 dropsite.tcl     checked for disclaimer - none
 dynhelp.tcl      checked for disclaimer - none
 entry.tcl        checked for disclaimer - none
 font.tcl         checked for disclaimer - none
 init.tcl         checked for disclaimer - none
 labelentry.tcl   checked for disclaimer - none
 labelframe.tcl   checked for disclaimer - none
 label.tcl        checked for disclaimer - none
 listbox.tcl      checked for disclaimer - none
 mainframe.tcl    checked for disclaimer - none
 messagedlg.tcl   checked for disclaimer - none
 notebook.tcl     checked for disclaimer - none
 pagesmgr.tcl     checked for disclaimer - none
 panedw.tcl       checked for disclaimer - none
 passwddlg.tcl    checked for disclaimer - none
 progressbar.tcl  checked for disclaimer - none
 progressdlg.tcl  checked for disclaimer - none
 scrollframe.tcl  checked for disclaimer - none
 scrollview.tcl   checked for disclaimer - none
 scrollw.tcl      checked for disclaimer - none
 separator.tcl    checked for disclaimer - none
 spinbox.tcl      copyright Unfix,Ajuba Solutions - does not disclaim license explicitly however removed from this system anyway.
 titleframe.tcl   checked for disclaimer - none
 tree.tcl         checked for disclaimer - none
 utils.tcl        checked for disclaimer - none
 widget.tcl       checked for disclaimer - none