Here’s some details about the program from the IRS:
You may access free commercial online tax preparation and electronic filing services through the IRS website . Eligible taxpayers may prepare and file their federal income tax returns using commercial online software provided by the Free File Alliance companies – not the IRS.
Free File is only available to taxpayers who have a 2007 Adjusted Gross Income (AGI) of $54,000 or less. Individual company offers may be limited to specific states and include other criteria. Carefully review the Free File offer criteria before selecting the company. Each participating software company sets its own eligibility requirements.
I actually used the program a few years ago to complete a basic return for a family member. It was easy to use and I would do it again.