Nailer writes "Bloomberg believe VMware's IPO today may the largest technology offering since Google. But doubts have been cast over the company's supposedly proprietary ESX product, as top 10 Linux contributor Christopher Hellwig claims the software may violate Linux kernel copyrights. 'Is Hellwig right, and is VMware a derived product of Linux? Unless vmkernel can be loaded without the Linux kernel, it would appear so. VMware was developed from another, long ago OS created as a research project, but it's unclear whether vmkernel was ported from that OS or rewritten as the Linux-requiring binary blob. What's more of an issue is that VMware had these serious questions posed directly to them a year ago, repeated in a public forum many times since, but have yet to respond at all.'"