VirtaMove Corp v. Microsoft Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: VirtaMove, Corp. (Canada)
  • Defendant: Microsoft Corporation (Washington)
  • Plaintiff’s Counsel: Russ August & Kabat
• Case Identification: 7:25-cv-00254, W.D. Tex., 05/30/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant resides in the district, maintains a regular and established place of business in the district, and has committed the alleged acts of infringement within the district.
• Core Dispute: Plaintiff alleges that Defendant’s Azure Kubernetes Service infringes a patent related to containerization technology that enables software applications to run on incompatible computer platforms.
• Technical Context: The technology relates to application containerization, a method for packaging software with its dependencies to ensure it runs reliably across different computing environments, a cornerstone of modern cloud computing.
• Key Procedural History: The complaint notes that Plaintiff's predecessor, Appzero, was identified by Gartner in April 2009 as a "Cool Vendor in Cloud Computing" with no direct technological competitors. It also states the USPTO examined the patented technology and concluded the claims were not disclosed or rendered obvious by prior art.

Case Timeline

Date	Event
2003-09-15	Priority Date for U.S. Patent No. 7,774,762
2009-04-01	Gartner "Cool Vendors in Cloud Computing" report mentioned
2010-08-10	U.S. Patent No. 7,774,762 Issued
2025-05-30	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,774,762 - "System Including Run-Time Software to Enable a Software Application to Execute on an Incompatible Computer Platform"

The Invention Explained

• Problem Addressed: The patent describes the problem of software applications being "typically designed to run on a specific computer platform, and will not run on one it is not designed for" (’762 Patent, col. 1:43-45). This incompatibility forces programmers to develop and maintain different versions of their software for each target platform, a time-consuming and expensive process (Compl. ¶14; ’762 Patent, col. 1:59-62).
• The Patented Solution: The invention proposes a system to run an application on an incompatible platform by packaging it in a "capsule" ('762 Patent, col. 3:48-53). This capsule contains the application itself along with the specific files (e.g., libraries) from its original, native operating system. "Capsule runtime software," which includes a kernel module and application libraries, then intercepts system service requests from the application. This software redirects the requests to the files within the capsule instead of to the host platform's incompatible files, thereby enabling the application to execute as if on its native platform ('762 Patent, Abstract; col. 2:27-49).
• Technical Importance: This approach allows "a single application that was only executable on a specific computer platform to now be used by a plurality of different computer platforms" without being rewritten ('762 Patent, col. 1:56-59).

Key Claims at a Glance

• The complaint asserts independent claim 17 ('762 Patent, col. 17:25-18:34; Compl. ¶18).
• The essential elements of independent claim 17 include:
  • Providing a set of files that includes both the first software application and a group of files specific to the operating system required by that application.
  • Executing the application on the incompatible platform by using this second group of files "in place of the associated local system files normally used to perform a same task."
  • Executing runtime software that includes a "kernel module resident in kernel mode" and at least one "application filter library resident in user mode."
  • This runtime software filters system service requests from the application and provides modified values from the application filter library, enabling execution by accessing the provided files instead of the host's operating system files.
• The complaint states that the accused products satisfy "one or more claims" and incorporates a claim chart for claim 17 by reference, suggesting it may assert other claims later (Compl. ¶18).

III. The Accused Instrumentality

Product Identification

The complaint identifies Microsoft’s Azure Kubernetes Service (“AKS”) as the representative accused product (Compl. ¶15).

Functionality and Market Context

The complaint alleges that AKS is a product used for containerization that infringes the ’762 Patent (Compl. ¶3, ¶15). It does not, however, provide specific technical details about the internal architecture or operation of AKS. The complaint contextualizes the market by noting that the application containers market was estimated at $5.45 billion in 2024 and is projected to grow rapidly (Compl. ¶5).

IV. Analysis of Infringement Allegations

The complaint references a claim chart in its Exhibit 2 purporting to show how AKS infringes claim 17 of the ’762 Patent (Compl. ¶18). As this exhibit was not attached to the publicly filed complaint, a detailed element-by-element analysis of the Plaintiff's infringement theory is not possible.

The narrative theory of infringement appears to be that AKS, as a container orchestration service, necessarily practices the patented method of running applications in isolated environments on potentially incompatible systems (Compl. ¶15). The complaint includes a "Virtualization Landscape" diagram from 2009, which positions Plaintiff's predecessor, "AppZero," in a unique quadrant for "Application" level virtualization, distinct from competitors focused on "Machine" or "OS" virtualization (Compl. p. 4). This visual suggests Plaintiff's infringement theory may focus on the specific layer of the technology stack at which AKS allegedly operates, arguing it aligns with the patent’s application-centric approach.

• Identified Points of Contention:
  • Scope Questions: A central question will be whether modern container orchestration, as implemented in AKS, falls within the scope of the claimed method. The patent describes solving incompatibility between distinct OS versions (e.g., Solaris 8 vs. Solaris 10). The dispute may question whether running a Linux-based container on a different Linux-based host, as is common in AKS, constitutes execution on an "incompatible computer platform" as the patent contemplates ('762 Patent, col. 2:50-62).
  • Technical Questions: The complaint does not specify how AKS's architecture maps to the claimed "kernel module" and "application filter library" ('762 Patent, col. 18:13-16). A key technical question for the court will be whether the mechanisms AKS uses to achieve isolation—which typically rely on native Linux kernel features like cgroups and namespaces—are the structural and functional equivalent of the specific two-part software architecture required by claim 17.

V. Key Claim Terms for Construction

• The Term: "incompatible computer platform"

• Context and Importance: This term defines the problem the patent purports to solve and is foundational to the infringement analysis. Its construction will determine whether the scenarios enabled by AKS (e.g., running containerized applications across different Linux distributions or kernel versions) are covered by the claims.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent provides examples of incompatibility between different versions of the same OS family (e.g., "Solaris version 2.6 to be placed into a capsule on a Solaris 9 platform") and between different distributions of the same OS ("Red Hat Enterprise Linux 4 (EL4) is placed in a capsule on a Suse Linux Enterprise Server 9 (SLES 9) or vice versa") ('762 Patent, col. 2:50-57). This may support an interpretation where any difference in the underlying OS or library environment that prevents an application from running constitutes "incompatibility."
  • Evidence for a Narrower Interpretation: A defendant could argue the term requires a more fundamental mismatch than minor version or distribution differences, although the patent’s explicit examples appear to counter this.

• The Term: "runtime software including a kernel module resident in kernel mode and at least one application filter library resident in user mode"

• Context and Importance: This term describes the specific technical implementation of the invention's solution. Infringement will likely depend on whether AKS's architecture can be fairly characterized as having this two-part structure. Practitioners may focus on this term because modern container platforms like Kubernetes achieve isolation using native kernel features (e.g., namespaces) rather than what might be characterized as a separate, add-on kernel module as described in the patent.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A plaintiff may argue the terms should be interpreted functionally to cover any software architecture where kernel-level and user-level components work together to intercept system calls and manage an application's environment.
  • Evidence for a Narrower Interpretation: The specification provides a specific description of this architecture, stating, "In kernel mode the system service filters are embodied in a loadable kernel module" and "In user mode the system service filters are embodied in a shared library" ('762 Patent, col. 9:18-28). This language may support a narrower construction requiring two distinct, structurally separate software components as described, rather than integrated native kernel functionality.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Microsoft encourages and instructs customers on how to use AKS in an infringing manner through "user manuals and online instruction materials on its website" (Compl. ¶16).
• Willful Infringement: The complaint alleges willfulness based on knowledge of the patent obtained, at the earliest, from the filing and service of the complaint itself, indicating a claim based on post-suit conduct (Compl. ¶16).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of architectural mapping: Does Microsoft's Azure Kubernetes Service, which leverages native kernel isolation primitives like namespaces and cgroups, implement the specific two-part software structure recited in claim 17, which requires a cooperative "kernel module" and "application filter library" for filtering system service requests?
• A key evidentiary question will be one of definitional scope: Can the term "incompatible computer platform," which the patent exemplifies with different OS versions or distributions (e.g., Red Hat on SUSE), be construed to cover the common cloud use case of running a container on a host with a different kernel or user-space library version within the same OS family (e.g., Linux on Linux)?