EasySetup interface (all its screens and menus) can be either in English or Spanish, either using the Preferences window or the View -> Language menu.
Also the program includes pre-made projects in English, Spanish, French, German, Portuguese, Italian, Dutch, Galician and Hungarian languages.
Use these projects as templates, by simply loading any of them and then configuring all your installation options, you will be able create installations in any of languages shown above.
Alternatively, if you wish, you can translate the project text to any western language and then save it under a different name.
EasySetup doesn't supports multi-byte character sets (MBCS), that means than languages like Chinese, Arabic or Japanese, are not supported. Learn more.