See the API list
Sort of easy, but there is a tedious need to define the call signature at call time. Survivable.
Generic external programs
simple enough, as I note at (julia plotting](./plotting_in_julia.html#svg-latex):
run(`inkscape -D -z --file=image.svg --export-pdf=image.pdf --export-latex`)
I should make an example of one which creates a temporary pipe and streams data to it.