We had recently worked with a client of ours to help port the Drupal 6 version of the Moneris Payment Gateway module for Drupal to Drupal 7. Moneris is a popular payment gateway in Canada.
The upgraded module has been submitted in an issue under the Moneris issue queue - https://drupal.org/node/1276770. Once it is tested and verified by the community the maintainer will be pushing the code to the repository.