Jay Maynard writes "IBM has broken the pledge it made in 2005 not to assert 500 patents against open source software. In a letter sent to Roger Bowler, president of TurboHercules SA, IBM's Mark Anzani, head of their mainframe business, claimed that the Hercules open-source emulator (disclaimer: I manage the open source project) infringes on at least 106 issued patents and 67 more applied for. Included in that list are two that it pledged not to assert in 2005. In a blog entry, the NoSoftwarePatents campaign's Florian Mueller said that 'IBM is using patent warfare in order to protect its highly lucrative mainframe monopoly against Free and Open Source Software.' I have to agree: from where I sit, IBM likes Open Source only as long as they don't have to compete with it."