Tools to improve English text

If anyone wants to contribute to the spelling dictionaries of codespell and spellintian (and the various other ones that exist, some of which are written for specific projects (hi qgis & kubernetes)), this is what I do:

Collect long lists of spelling mistakes you have noticed in code, email, blog posts, news articles, forum comments and so on.

Use the Debian code search engine to find if anyone has made that spelling mistake in reasonably popular open source code.

https://codesearch.debian.net/

Use the regex mode to detect other variants of that spelling mistake, for example if you started with "expund" then search for "expun[a-ce-z]" and you will soon find "expunf" etc.

Wade through tens of pages of false positives looking for useful results.

Manually add obvious variants of each spelling mistake (add "expunds", "expunding" when you have "expund" already).

Review the result and semi-automatically create commits and PRs.