principle shall apply to the legal hybrid software to provide a judicious balance between property rights of the title holders and freedom rights of computing professionals and society as a whole, is in dispute. Debate There is a debate over the extent to which software patents should be granted, if at all. Important issues concerning software patents include: Whether software patents should be allowed, and if so, where the boundary between patentable and non-patentable software should lie; Whether the inventive step and non-obviousness requirement is applied too loosely to software; and Whether patents covering software discourage, rather than encourage, innovation; Whether software based on mathematical methods may be allowed if the mathematics or algorithm in question is complicated enough and may not be implemented with pencil and paper. Open source software There is strong dislike in the free software community towards software patents. Much of this has been caused by free software or open source projects terminating when the owners of patents covering aspects of a project demanded license fees that the project could not pay, or was not willing to pay, or offered licenses with terms that the project was unwilling to accept, or could not accept, because it conflicted with the free software license in use. Several patent holders have offered royalty-free patent licenses for a very small portion of their patent portfolios. Such actions have provoked only minor reaction from the free and open source software communities for reasons such as fear of the patent holder changing their mind or the license terms being so narrow as to have little use. Companies that have done this include Apple, IBM, Microsoft, Nokia, Novell, Red Hat, and Sun (now Oracle). In 2005 Sun Microsystems announced that they were making a portfolio of 1,600 patents available through a patent license called Common Development and Distribution License. In 2006, Microsoft's pledge not to sue Novell Linux customers, openSUSE contributors, and free/open source software developers over patents and the associated collaboration agreement with Novell was met with disdain from the Software Freedom Law Center while commentators from the Free Software Foundation stated that the agreement would not comply with GPLv3. Meanwhile, Microsoft has reached similar agreements with Dell and Samsung, due to alleged patent infringements of the Linux operating system. Microsoft has also derived revenue from Android by making such agreements-not-to-sue with Android vendors. Unisys case In the late 1990s, Unisys claimed