Why a Leading Linux Developer Gave Up the VMware GPL Lawsuit

Background

VMware’s ESXi hypervisor (vSphere ESXi 5.5.0) incorporates code from the Linux kernel. The Linux kernel is released under the GNU General Public License version 2 (GPL‑v2), which imposes a “copyleft” requirement: any software that combines GPL‑v2 code with other code must itself be distributed under GPL‑v2 and the complete corresponding source must be made available.

Technical Issue

VMware released a component called vmklinux that contains the Linux kernel sources, but the surrounding management component, vmkernel, remained proprietary. Because vmkernel links with the GPL‑licensed kernel code, the combined work is a derivative of GPL‑v2 software. Under the license, VMware was obligated to publish the full source tree for the combined vmkernel + Linux code, which it did not do.

Legal Actions

2006 – Linux developer Christopher Helwig discovers the alleged GPL violation.

2015 – Helwig, assisted by the Software Freedom Conservancy, files a lawsuit against VMware in the United States.

2016 – The district court dismisses the complaint, finding insufficient evidence that VMware’s proprietary component is a derivative work.

Subsequent appeal – The appellate court upholds the dismissal.

After the second appeal is rejected, Helwig announces he will no longer pursue further litigation, citing the high evidentiary burden and the extensive time and resources required for individual developers to enforce GPL compliance.

Arguments Presented

The plaintiff argued that VMware combined GPL‑v2‑licensed Linux code with its proprietary vmkernel and distributed the combined binary without providing the complete source under GPL‑v2, thereby breaching the copyleft provision. VMware counter‑claimed that the allegations lacked a legal basis and that the plaintiff had not demonstrated ownership or copyright of the combined component.

Outcome and Industry Impact

VMware later announced that future hypervisor releases would no longer embed Linux kernel code, effectively removing the GPL‑v2‑covered portion from its proprietary kernel. The Software Freedom Conservancy reiterated that compliance with FOSS licenses is mandatory; copyleft is both a legal requirement and a core community norm.

Related GPL Enforcement Example

A recent incident involving Tencent’s kernel team illustrates similar enforcement challenges. The team released the TCPA project based on Red Hat Enterprise Linux 7.4 source code, which is GPL‑licensed, but failed to publish the required source for the derived work. The project was subsequently taken down.

These cases underscore the practical difficulties of enforcing GPL compliance against large vendors and highlight the importance of clear licensing practices when integrating open‑source components into proprietary products.