BLT is an extension to the Tk toolkit. BLT's most useful feature is the
provision of more widgets for Tk, but it also provides more geometry managers
and miscellaneous other commands. Note that you won't need to any patching
of the Tcl or Tk source file to use BLT, but you will need to have Tcl/Tk
installed in order to use BLT.
This package provides headers needed to build packages based on BLT.
