For developers working with .NET and .Net Framework applications that need multi-language support using the Microsoft Localization and Internationalization (MAT) framework, which uses XLIFF for translation exchange.
Since Microsoft discontinue Multilingual App Toolkit on October 15, 2025 and is not fully compatible with Visual Studio 2026 I've decided to create this very simple extension that fills the current gap. I'm using it effectively I my current job and it will be update soon until a good closed version.
I'll publish in GitHub very soon a complementary tool, an Avalonia Xilff editor for Windows and Linux, that lets you to translate manually or using Azure API.

Yes! It exists!
Language Manager
Go to Language manager from "Tools > Language manager"

Language manager let's you:
Add language resources: Strings.{lang}.resx and {project_name}.{lang}.xlf to an existing project.

Add a new language to an existing language project: Strings.{new_lang}.resx and {project_name}.{new_lang}.xlf.

Flow
When Strings.{lang}.resx and {project_name}.{lang}.xlf created then:
- Add new language resources in Strings.resx (base language) then will be created in xlf files as not translated.
- Translate *.xlf files manually, with 3rd party service, using a xliff tool or using my XliffTranslator Avalonia Project that uses Azure API translation (API key required).
- Compile project, then Strings.*.resx will be updated with language resources translated..
- Use new language resources in you application.