- Thesaurus - there are a few different packages, powerthesaurus, le-thesaurus, etc. I use mw-thesaurus, at this point mainly out of habit, it's the first Emacs package I ever made and it served me so well, I never had reasons to look for alternatives.

- Spellchecking - I suppose flyspell still holds the majority, I prefer jinx.el, it completely replaced flyspell for me

- translation - also multiple choices, from translate-mode, org-translate, ob-translate, lingva, immersive-translate, etc. I use google-translate - for no particular good reason, it's just an old habit.

- search - consult-omni, it takes some initial tweaking, but then you can simultaneously search on Google, Wikipedia, YouTube, your browser history, etc., while typing the query once.

- dictionaries - sdcv

- etymology - define-it, wiktionary-bro

- word counter - is built-in; reading ease testing - writegood.el

- LLMs - multiple choices, gptel and chatgpt-shell are the most popular.