How can PHP be used to implement spell checking on a server?

To implement spell checking on a server using PHP, you can utilize a library like `pspell` which provides functions for spell checking. You would need to install the `pspell` extension for PHP and then use functions like `pspell_new`, `pspell_check`, and `pspell_suggest` to perform spell checking on input text.

// Create a new pspell instance for the English language
$pspell_link = pspell_new("en");

// Check if a word is spelled correctly
$word = "hello";
if (!pspell_check($pspell_link, $word)) {
    echo "Did you mean: ";
    $suggestions = pspell_suggest($pspell_link, $word);
    echo implode(", ", $suggestions);
}