A level editor (plus a few other tidbits) for the Famicom game Layla, used in the development of Layla: The Iris Missions. I doubt anyone else has a use for this, but if you want to edit the game, it should be up to the task. It can also make maps, though even those won't help you much with the original game's labyrinths.
A command line program that compiles music written in a purpose-built scripting language to the binary format used by Layla's sound driver. Used in the development of LTIM's soundtrack. I really doubt anyone else has a use for this, but hey, it works. The Github repo contains example files and documentation for the scripting language.