Hello,
We'll think about it. Thank you for your time.

There's nothing especially "wrong" with it, it just doesn't offer any actual localization features and requires managing files directly on translators side. It's not nearly as accessible for inexperienced users and it makes collaboration more difficult (especially on a string by string level). With a platform like Crowdin, translators could freely add suggestions, vote for other people's suggestions and some could act as proofreaders who approve correct/best suggestions. Additional productivity features could include, string specific comments, contextual information, glossaries for terminology (with automatic highlighting), automatic translation memory functionality and also support for many machine translation platforms among other things.

Obviously FDM is not a very large project and the implementation would change require work on your side but these platforms can make things very easy and accessible for much larger localization communities than what code repositories like GitHub are able to do (as long as the projects are public).

Hello,
What's wrong with GitHub for you?

First of all, thanks for still developing a traditional download manager, there aren't many of those left these days (I have used FDM for many many years).

As for the actual topic, I would very much like to translate FDM into Finnish and also importantly keep maintaining the translation for years to come. But I really, really (like really) dislike editing language files directly (or at GitHub) as it makes collaboration difficult and translation quality assurance super complicated even for smaller projects like FDM. And I would hate to provide a low quality, unprofessional translation that I would find too cumbersome to maintain over time which is why I haven't done it.

I am an active translator and proofreader on many projects that are hosted on platforms like Crowdin, Weblate and Transifex to name a few and would very much like to see FDM on one of these platforms. I'm personally a big fan of Crowdin because of it's minimalistic UI (that also works well on mobile browsers) and great basic features (like a glossary), and I can also recomend Weblate very much. Of these Crowdin offers a free plan that is suitable for most smaller public projects and Weblate is open source and you can host it yourself if you want to.

See:
https://crowdin.com/pricing#crowdin-pricing-key-features
https://weblate.org/en/hosting/

My Crowdin profile is public so feel free to check out what I have worked on there: https://crowdin.com/profile/olavinto