It wasn't a script as such, just a built-in tool in Inkscape: "Create Tiled Clones" -- simply make a blue rectangle with a radial gradient at about 50% opacity, use the Tiled Clones tool to make lots of horizontal duplications, slightly altering opacity, height, position and angle (by about 1.5 degrees max). Finally I added an overlay to add a bit of depth and contrast in GIMP.
It wasn't a script as such, just a built-in tool in Inkscape: "Create Tiled Clones" -- simply make a blue rectangle with a radial gradient at about 50% opacity, use the Tiled Clones tool to make lots of horizontal duplications, slightly altering opacity, height, position and angle (by about 1.5 degrees max). Finally I added an overlay to add a bit of depth and contrast in GIMP.