After a year of waiting this website is upgraded to Drupal 8. All the content is migrated, but we are missing some functionality. But overall the migration went well.
In the meantime, it turns out that this website is already more then 10 years online! Never thought that would happen. It started with Drupal 5 to Drupal 6 migration in 2006 ( https://theyosh.nl/website-upgrade ). And now we are almost 12 year further. The last couple of years it was a bit quiet, but there will be new updates soon.
In the meantime, we have had
New information about the above projects will be soon on this side