Ubuntu is a well known free, open source based Linux based operating system. Their business model is to provide software free of charge but to make money by giving support instead. Recently there have been a large number of variants of the program named with *buntu for example the program Ubuntulite. Many of these programs have started receiving letters telling them that naming their programs in this manner is a violation of the Ubuntu trade mark. Ubuntu’s Trade Mark Policy states.”We would strongly discourage, and likely would consider to be problematic, a name such as UbuntuMan, Ubuntu Management, ManBuntu, etc. Furthermore, you may not use the Trademarks in a way which implies an endorsement where that doesn’t exist, or which attempts to unfairly or confusingly capitalise on the goodwill or brand of the project.” Their policy is in accordance with the established norms of trademark law.
The interesting thing about this story is that tm enforcement is becoming more common in the open source community. Linux seldom issues this type of cease and desist but other open source companies have started doing it like Redhat for example. There has been a lot of controversy about other areas of IP and how it relates to open source. For example the notorious copyright cases from SCO earlier in this decade. It has only been recently that tm concerns are being reported. The problem that many companies realize is that to keep a trade mark you have to enforce your rights making sure that the name is not becoming generic or being diluted.
Anyone who uses any kind of open source licence should realize that the licence has some strict restrictions. When developing software or anything else under such a licence it is good to assess early on how it will restrict you and if that restriction will conflict with your ultimate goals for example if you want to sell your program.
Most of the time even though open source licences are free they often come at a price.