We've always advocated cross-platform development -- in fact, last year, we wrote a post explaining why you should support Mac OS X and Linux. When organizing the Humble Indie Bundle, we decided to put our money where our mouth is and only select games that support all three major desktop platforms: Mac, Windows, and Linux.

At the moment, we have about 53,500 donations -- far more than we expected! But where did they come from? Our breakdown for number of donations per platform is: 65% Windows, 21% Mac, and 14% Linux. However, when we look at the amount donated per platform, we see something different. Our breakdown for total donation size per platform is 52% Windows, 25% Mac, and 23% Linux. Here are these results in pie chart form:

This could only be explained if Mac and Linux users are making much higher contributions than Windows users. So far, the average Mac user is donating 40% more, and the average Linux user is donating 100% more! Here is a bar graph showing the different average donation amounts:

If you'd like to see real-time updates to the average donation per platform, I've modified the stats section of the bundle page. Click here to check it out. These averages have stayed rock solid for the last three days, but now that they are visible on the site, it will be interesting to see if they change!