Filling out tax returns has traditionally been an area where Linux comes up short compared to the proprietary platforms, but you actually have several options for using commercial income tax products on a Linux platform. Here's a quick look at three commercial tax offerings I found that work just fine using Ubuntu 7.10 and Firefox 2.0.0.12, even though two of the three vendors warn Linux users they are not supported. Translation: Don't look for vendor help if you run into problems.