SkyTemple Randomizer is a free and open-source application that works on all major OSes (Windows, macOS, and most Linux distributions).
What is SkyTemple Randomizer?
It’s a ROM hacking tool that allows you to randomize almost every aspect of the game Pokémon Mystery Dungeon Explorers of Sky played on some older Nintendo devices and Wii (such as the Wii U).
In short, it provides you with a clean and easy-to-use GUI for changing everyting from NPCs, to dungeon layouts, starters, chapters, and many more.
It can do all this via a Python library (used for editing the ROM through Python (skytemple-files), and a built-in debugger/script editor (skytemple-ssb-debugger) that allows you to edit the game’s scripts via the ExplorerScript programming language.
Feature rundown
One thing that is apparent is the level of commitment and work that has gone into making this tool. The developer and various members of the community (mostly PMD ROM hackers), have done a great job at reverse engineering the ROMs.
The result is a very straightforward app that features a map background editor, a scene editor, a script editor/debugger, a dungeon editor, a dungeon tileset editor, and a fixed room/boss fight editor.
SkyTemple Randomizer also allows you to edit data of Pokémon, including portraits, base stats, and move learnsets. More features include the ability to apply ASM patches to add new functionality to the game, edit various other small miscellaneous graphics (fonts, message boarders, etc.), and the freedom to edit all the text in the game.
Conclusion
Before we conclude, it’s worth noting that SkyTemple Randomizer is in no way affiliated with Nintendo, The Pokémon Company, Spike Chunsoft or any of their affiliates, as its a totally unofficial project build and actively maintained by a community of passionate people.
For more information about this amazing little project, please feel free to check out the official website, as well as this thread on the game’s official forum.