Fork OpenUtau and develop a new editor

Overview

This page describes the minimum set of changes required when forking OpenUtau and distributing a new editor.

Several OpenUtau-based editors have recently been released without modifying application identifiers, installer settings, update sources, or configuration storage locations. As a result, users have encountered issues such as:

• OpenUtau settings being overwritten by a forked editor
• OpenUtau becoming unable to start due to incompatible configuration files
• Installation and uninstallation information being overwritten
• File associations being unexpectedly changed
• Forked editors updating from the official OpenUtau release channel

The purpose of this document is to help developers avoid these conflicts and ensure that forked editors can coexist safely with the official OpenUtau installation.

This page focuses on identifying the locations that should be reviewed and modified before distributing a forked editor. Some items are required to prevent conflicts, while others are recommended to improve identification, branding, and user experience.

This document assumes the following coexistence model:

• Voicebanks may be shared with OpenUtau.
• External tools and dependencies may be shared with OpenUtau.
• User preferences, application settings, installer identifiers, and update channels must not be shared with OpenUtau.

Following the recommendations in this document helps prevent user environment corruption and reduces support issues caused by conflicts between OpenUtau and forked editors.

Modification Procedures

Modification List

Category	Target for Change	Main Files to Change	Priority	Reason
Settings Save Location	PrefsFilePath	OpenUtau.Core/Util/PathManager.cs	Required	To prevent corruption and startup failure caused by sharing the same settings file.
Installer Product Name	PRODUCT_NAME	OpenUtau.nsi	Required	To prevent overwriting uninstallation information.
Uninstall Key	PRODUCT_UNINST_KEY	OpenUtau.nsi	Required	To prevent Windows Registry conflicts.
Installation Path	InstallDir "$PROGRAMFILES64\OpenUtau"	OpenUtau.nsi	Required	To prevent overwriting the original version's installation directory.
Shortcut Name	OpenUtau.lnk	OpenUtau.nsi	Required	To prevent overwriting the Start Menu and Desktop shortcuts.
Executable Name	OpenUtau.exe	OpenUtau.nsi, OpenUtau/OpenUtau.csproj	Required	To prevent the installer and shortcuts from referencing the wrong executable file. To ensure users do not mistake it for the original version.
Updater	GitHub Release Repository	OpenUtau/ViewModels/UpdaterViewModel.cs	Required	To avoid the risk of users updating to the original version by referencing the original GitHub Releases.
.ustx Association	HKCR ".ustx" / OpenUtauFile	OpenUtau.nsi	Recommended	If not changed, it will take over the original version's file association. However, this is not mandatory as users can change it later.
USTX Version	kUstxVersion	OpenUtau.Core/Format/USTx.cs	Recommended (Conditional)	Targeted for change only if the USTX format is uniquely modified.
File Selection Filter	Patterns	OpenUtau/FilePicker.cs	Recommended (Conditional)	Targeted for change only if handling unique extensions or formats.
GitHub / Web Links	Wiki / Website URL	OpenUtau/Views/MainWindow.axaml.cs	Recommended	To avoid misleading users to the original version's information.
Crowdin workflow	Crowdin Project / Token	.github/workflows/crowdin.yml	Recommended	To prevent synchronization errors with the original translation and malfunction of bot settings.
Translation Sync Script	Crowdin Project Identifier	Misc/sync_strings.py	Recommended	Change if you intend to manage translation assets independently.
Splash Window	Logos and icons in SplashWindow.axaml	OpenUtau/Assets/*, OpenUtau/Views/SplashWindow.axaml	Recommended	For visual distinction from the original version
Icon	open-utau.ico	OpenUtau/Assets/*	Recommended	For visual distinction from the original version