Vlad
I am not sure how closely you follow FireFox's development, but Mozilla has this one sort of 'solved' in FireFox now. Bergamot is a purely client-side translator with support for a variety of European languages.
Unfortunately, the public's general awareness of its existence seems pretty bad right now - I would guess likely in part due to the fact that it is implemented as an official extension rather than a feature baked into every copy of FireFox. However, it works shockingly well for what it is, often times better than what I have seen from Safari.
The only major feature that Apple's translation really has over Bergamot/FireFox's, to me as an end-user, is support for a few more critical language pairs (e.g., EN<>ZH, EN<>JP). On the other hand, Mozilla's is totally open and relatively easy to extend, at least for languages with an alphabet.
I have not had the time, unfortunately, to really dig into the code since its release to see how much effort it'd be to get it working on other browsers. But I did stumble across an experimental fork with Chromium support as well. Might be worth looking into!
Regardless of which API (or, hey, maybe it'd be possible to offer alternate backends?), one thing that I would really love to see that Safari and most other browsers seem to get frustratingly wrong is the ability to force-translate a page with a user-selected language; if a page contains both the user's preferred language and a foreign language, unless it is comprised overwhelmingly of the foreign language, many browsers simply don't allow the page to be translated.
This happens to me regularly with Safari when browsing Chinese and Russian forums and such that offer a user-selectable UI language -- all the content remains untranslated and in Chinese, presumably because Safari sees the English navigation bar and assumes there must be some sort of false-positive. The same thing often occurs when Googling in a foreign language - the results can remain untranslated due to the UI language.
In that sense, desktop Chromium is one of the very, very few that I find to be pleasant in terms of translation from a UX perspective. It will autodetect and offer translations when possible, but you can still manually just right-click -> translate, and then it just works.
I have been following Orion's development for quite a long time now after coming across it on HN. I'd love to make it my daily-driver. But this is, sadly, one of those critical features I use a ton. Hoping to see support for some sort of solution in the future!
EDIT:
I'm a broke university student, so it's not a ton, but I tossed in $20 with the PayPal sponsorship button for now.
(p.s. the 'sponsor issue' feature doesn't seem to actually redirect you anywhere to link a donation to a particular request - not sure if that is a known issue. PP IDs: 69G9501595466880F 728202188A490324F)
