I would love to support Julia. It seems that there was some success here: NotebookAdapter.mime_type is undefined · Issue #313 · krassowski/jupyterlab-lsp · GitHub and here https://twitter.com/sig_kdy/status/1237696242068500480/photo/1 (possibly with some drawbacks) but since no one ever opened an issue on our GitHub or asked us for help so it has never become a supported server. If you wish to change that, please open an issue, or better - a PR.
With the release of jupyterlab-lsp 3.1, we now support auto-detection of Julia Language Server (LanguageServer.jl) as an experimental feature:
Please do report bugs and feel welcome to send pull requests to improve it
Thank you, Michał. I did poke around with the solutions you mentioned in the previous reply, but couldn’t provide more time to investigate why the language server doesn’t get detected. Anyway, I will give this experimental feature a go as soon as I can.