How can PHP developers ensure that their code is compatible with different operating systems when retrieving system information?

PHP developers can ensure their code is compatible with different operating systems by using PHP's built-in functions that abstract system-specific details. For retrieving system information, developers can use functions like `php_uname()` or `phpinfo()` which provide system information in a standardized format regardless of the underlying OS.

// Retrieve system information using php_uname()
$systemInfo = php_uname();
echo $systemInfo;

// Retrieve system information using phpinfo()
phpinfo();