I think nobody has really explained how karma is currently calculated for appliactions (Products in profile page).

You get couple of points (<10) for having an application in maemo.org/downloads, then you get additional points for the rating. Maximum karma for one application is 45 or so. I couldn't find the formula so this is from memory. There is no karma for downloads.

Garage karma is called Groups in profile page. If you have single project where you are the maintainer you get 9 points ( I think it is 3 for having an account, 3 for being member of a project, 3 for being maintainer of a project)