Tcl/Tk provides easy GUI creation. Connection between newLISP and Tcl/Tk is done via pipe. See my souped-down Script tk.lsp:
//http://wolf-dieter-busch.de/html/Software/newlisp/doc-2023-01-06-14-56-24.htm
Because standard I/O is connected to the pipe, no read-eval-print loop via keyboard possible. So I have done an emulation via Tcl/Tk. Newlisp script rep.lsp calls Tcl script rep.tcl:
//http://wolf-dieter-busch.de/html/Software/newlisp/doc-2023-01-06-14-46-03.htm
//http://wolf-dieter-busch.de/html/Software/newlisp/doc-2023-01-06-14-48-16.htm
Plaintext description in German:
//http://wolf-dieter-busch.de/html/Software/doc-2023-01-06-14-28-41.htm
Feel free to try it out. Bug report welcome!
Update -- wrong target corrected for rep.tcl; from now on errneous lisp statements trigger a Tcl/Tk message.