Lingva is awesome. Also don't forget to check out LibreTranslate and Apertium. They both are open source. Apertium can even translate documents and web pages!
Potential google translate replacement.
For those who are familiar with python, if you have Linux or Mac OS, it runs locally as a Flask app.
On Windows, the author recommends running it though docker.
Looks promising from my initial test on Linux. There is a demo instance running online here.
OK, I managed to write Python-based "scraper" which is able to translate ANY RSS 2.0 feed from some language to another.
It uses https://libretranslate.com self-hosted instance (which is free and open source), but SLOW. VERY SLOW.
Depending on the number of articles inside the RSS feed, it takes minutes to translate it and requires you to install LibreTranslate via Docker or Python.
It would be better to use for example Google Translate API, but it is not free.