Microsoft’s original source code

I still haven't seen anyone using a spellchecker in code outside of IntelliJ

Some people use VSCode extensions

Emacs has the ability to do spellcheck inline, both as a run through the buffer (old-school style) and as an as-you-type live feature. That said, I do most of my coding in JetBrains IDEs these days.

cSpell alone has 13 million installs

https://marketplace.visualstudio.com/items?itemName=streetsi...

I recently found https://github.com/tekumara/typos-lsp that uses https://github.com/crate-ci/typos Plenty of GH stars so likely a solid user base. Works great in NeoVim with the built-in apellchecker.

Eclipse has had an integrated spell-checker, which I believe is on by default for most file types, for like approximately forever. Now maybe everybody turns it off, but I gotta imagine there are some people who like it and keep it on.

For Vim/Neovim users, there is one built in that is pretty good, and once you've added frequent custom words to the dictionary it is great. You can turn it on with `:set spell` or off with `:set nospell`. Add custom words by pressing `zg` on the target word:

I have this in my vimrc file so it's on by default for certain file types:

    " Turn on spellcheck for certain filetypes and word completion.                                                                                                                                                                               
    " words can be added to the dict by pressing 'zg' with cursor on word.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
    autocmd Filetype markdown setlocal spell                                                                                                                                                                                                      
    autocmd Filetype gitcommit setlocal spell                                                                                                                                                                                                     
    set complete+=kspell                                                                                                                                                                                                                          
                                                                                                                                                                                                                                              
    " Don't highlight in red an underscore (_) in markdown                                                                                                                                                                                        
    " https://vi.stackexchange.com/q/18471/17441                                                                                                                                                                                                  
    autocmd Filetype markdown syn match markdownIgnore "\v\w_\w"

Custom additions to the dictionary will go to a simple text file (one word per line) in `~/.vim/spell/en.utf-8.add` (depending on your settings) where it is easy to edit or backup.

"apellchecker" is actually a great name for a spellchecker

Codespell works very well, in my experience. I run it from the command line and in CI.

https://github.com/codespell-project/codespell

> custom additions

You can also add it directly when using it. Move the cursor to the word and (I forget the command...) can add it as a rare word, good word or bad word.