For editing a project in both GM IDE and GMEdit at once,
- GM IDE has a setting in “menu:File ➜ Preferences ➜ General ➜ Automatically reload changed files”.
- GMEdit has a setting in “menu:Preferences ➜ File handling ➜ If the source file changes”. “Reload unless conflicting” is what you’ll usually want.
GMLive doesn’t care how you are editing the project, the server watches files for changes.