I've been running workshops recently to explain the different kinds of open source licences, and what they're used for. Many are suitable for a commercial environment; some are certainly not. The key thing is that FOSS (free and open source software) is still covered by copyright law and its accompanying licence, however liberal, is still likely to contact restrictions on how the code can and cannot be used. There really is no escaping the small print.
A new study has suggested that while nearly 80% of firms are making use of open source software, the vast majority of them have no formal policies to accommodate for its existence in place.