Binary package “tkblt-dev” in ubuntu focal

Graphics extension library for Tcl/Tk (development files)

 TkBLT is a derived version of the BLT Toolkit by George A. Howlett,
 for Tcl/Tk 8.5/8.6, is TEA compatible, and is fully compatible with
 the Tk API. TkBLT includes only the Graph and Barchart Tk widgets,
 and the Tcl Vector command.
 .
 This package contains the header files and the package stub library.