I wanted to follow up with some additional details from our experience getting Linguise working well with Discourse.
First, on our site we use the Discourse SAML plugin for authenticating users against a different user store. We found that there was a cookie issue in that particular case.
Fortunately the folks at Communiteq (https://www.communiteq.com/), who are an excellent hosting company for Discourse, were able to analyze the issue and create a tiny fix in the form of a plugin to resolve it. But for most folks it won’t be needed.
There is one limitation you should be aware of; Linguise does no translation when it is running in whatever its default language is, in our case, English.
Normally this is not an issue but there is one case where it is—Posts authored in another language, say Spanish, appear in Spanish when Linguise is set to English. In any other language, they would get translated, but not in the default language.
Linguise may improve this going forward, but there is no commitment.
The workaround for this is to also make use of the Discourse Translator plugin. You need to set up access to one of the translation companies (Google, Yandex, Microsoft, etc.) API, then configure those credentials in the plugin.
Once you do that, if you are in English and reading a post created by someone in Spanish, you will see a small globe icon
Clicking that causes a translation to appear underneath the original.
Between the two, it covers all cases, although not as elegantly as I would have wished.
We use a Google Cloud account that gives the first 500,000 words each month for free, and we rarely exceed that limit. I think other vendors have similar deals.
I hope this is helpful for someone.