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.
The upgraded module currently does not support recurring subscriptions. If there are users who are looking to get recurring payment support enabled for Moneris in Drupal 7 we will be happy to help with the development and maintenance of the same. We would require that you allow us to contribute these changes back to Drupal.org :)