you read my mind! This is what I had in mind and wanted to know if it was possible or not. The subprocess module that @FedericoPerini created is really a brilliant key step towards that!!
I would like to see a stdlib_plot module which would be a frontend giving a high-level API and which can sit atop plotting backends such as gnuplot, plotly, matplotlib (?). gnuplot can be a good starting point and default backend.
I’ve found this project GitHub - kookma/ogpf: ogpf is Object based interface to GnuPlot from Fortran 2003, 2008 and later to get quite close to the idea regarding the user experience. The Fortran API resembles enough matplotlib to make it quite easy to use. Using the subprocess approach would avoid the need of using intermediate files and I would vouch also for it being within stdlib or strongly depend on it to avoid code duplication and ecosystem fragmentation.