Turbo Tax Online
Background
Turbo Tax Online is convenient way to file federal income tax in the United States through a web browser. Your author has used Firefox on Linux to file his taxes 2001 - 2007.
However, as of January 2008, that website is now checking the user agent string reported by Firefox to specifically exclude Linux users.
Modifying Firefox's User Agent String
Fortunately, it is trivial to change the user agent string in Firefox and step around this disappointing exclusion.
Point Firefox to the special url: about:config
Filter on the string useragent
Change the value of general.useragent.vendor from Ubuntu to Windows
Change the value of general.useragent.vendor from gutsy to Windows NT 5.1
Now, try http://turbotax.intuit.com/ again.
Don't forget to change your general.useragent.vendor and general.useragent.vendor values back to their originals when you're done!
An alternative method of changing your user agent string is to install the user agent switcher add on for Firefox. It is useful in any situation of this type and then you don't have to remember the string instructions. Remember to reload the page after switching user agents.
Alternative Approach
For now, it seems that this link bypasses the system requirements check (for now):
Disclaimers
It is possible that the good people at Turbo Tax have a reason for excluding Linux users. Their technical support team has been contacted to report the problem. The response has been that Turbo Tax only supports Windows and Mac users.
In the meantime, one may use the above workaround.
References