Choice of processor

[William F Hammond]

David Carlisle writes in part, quoting Peter Flynn:

   Most luatex users don't need to code in lua, it's just
   available if you want it.

   On 02/03/2025 15:28, David Carlisle wrote:
      See
      https://www.texdev.net/2024/11/05/engine-news-from-the-latex-project 

In following that link I see that the use of luatex is now
recommended for all new documents.  Further it says that
xetex users will need to make some changes to move to
luatex.  Is there a quick reference for such changes?
(Otherwise I suppose one may call texdoc for luatex.)

                              -- Bill