The question Websites that allow communication between people: List asks for a list of websites. Should we turn this into a community wiki? I think we haven't used this format yet on LLSE.
Using Community Wiki was at one time considered the proper way to handle these "list questions" on SE. That time was several years ago. The more modern approach is more often simply not to allow such questions. I agree with this, and think that particular question should be closed. It's not only a list question, with literally thousands (or more) proper answers. The correct answers change daily as new web sites are created, and old ones closed. It's not our job to catalog such sites. Google does that pretty well already.
A better approach to such questions, which is taken on many sites, is to create a list of common/popular resources on meta. Spanish.SE has recently renewed this effort.
A (small) list of such sites might fit on such a page. Before we jump to that conclusion, though, I'd suggest we open that specific idea for discussion at large. We may want one post per language, rather than just a single post. Or maybe we want a single post, with sections per language? And maybe this community does want such a post on the main site rather than meta, etc. I encourage you (or anyone) to put forth a proposal for this here on meta. If nobody else does, I might do it myself when time permits.