It is true that this card, and related 3ware cards, are supported by free software Linux drivers. However, that's only half the story. Are there any free software *userspace* tools for interacting with these cards? As far as I'm aware (please correct me if I'm wrong) the only existing tools for configuring and monitoring the RAID are the non-free programs 'tw_cli' and '3dm2'. Without these tools installed, you can access arrays that have already been configured - but you cannot create or reformat arrays or change the configuration. Even routine maintenance often requires the use of tw_cli. So without proprietary software, this card is pretty useless.