X1 Discovery, Inc. v. Microsoft Corporation

X1 Discovery, Inc. initiated patent infringement litigation against Microsoft Corporation in the U.S. District Court for the Central District of California (Case No. 8:23-cv-02415). X1 Discovery, Inc. is a privately held software company based in Pasadena, California, specializing in products for rapid information retrieval, particularly in the eDiscovery and social media sectors, indicating it operates as a product company. Microsoft Corporation is a global technology conglomerate renowned for its software, services, and hardware offerings, including operating systems, cloud computing, and productivity applications. The accused products in this litigation include Microsoft Search and File Explorer Search within Windows 10 and 11, as well as Microsoft 365 Search and SharePoint.

The central patent at issue is U.S. Patent No. 10,552,490, titled "Methods and Systems for Search Indexing." This patent generally relates to novel and reactive search methods and systems that display search results rapidly, updating them in real-time, and in fewer steps than conventional search software. While originally asserting multiple patents, the '490 patent expired on November 8, 2024, during the course of this litigation. The case is currently active in the Central District of California, which is a significant venue for intellectual property disputes, participating in the Patent Pilot Program. The case has experienced several judge reassignments, with Judge George H. Wu now presiding over the proceedings.

This litigation is notable as it appears to be part of a broader patent enforcement campaign by X1 Discovery. Microsoft has filed inter partes reviews (IPRs) challenging the validity of several X1 Discovery patents, including IPR2025-00255 which targets the '490 patent. Additionally, X1 Discovery has initiated parallel patent infringement actions before the International Trade Commission (ITC) and in other district courts against companies like Acer, ASUSTek, and Dell, asserting related search and data discovery patents against their computing devices. The fact that the '490 patent expired while the litigation is ongoing may influence the remedies sought, shifting the focus towards past damages rather than prospective injunctive relief.

X1 Discovery, Inc. sued Microsoft Corporation for patent infringement of US patent 10552490 (among others) in the U.S. District Court for the Central District of California on December 19, 2023. The case, numbered 8:23-cv-02415, is currently active.

Here's a chronological overview of the key legal developments and outcomes:

Filing & Initial Pleadings:

• December 19, 2023: X1 Discovery, Inc. filed a complaint against Microsoft Corporation in the U.S. District Court for the Central District of California, alleging infringement of U.S. Patent Nos. 7,370,035, 9,633,139, 10,552,490, and 8,498,977. The lawsuit claims that Microsoft directly and indirectly infringes one or more claims of these patents, particularly through its Microsoft Search feature in Windows 10/11 and Microsoft 365 operating systems and services.
• The '490 patent, titled "Methods and Systems for Search Indexing," expired on November 8, 2024.
• December 21-27, 2023: The case underwent several reassignments, moving from Judge James V. Selna to Judge John A. Kronstadt, and then to Judge George H. Wu.

Pre-trial Motions of Substance:

• As of the latest available information, there are no specific docket entries indicating substantive pre-trial motions such as motions to dismiss, transfer, or summary judgment being decided in the district court case. The focus appears to be on parallel PTAB proceedings.

Claim Construction (Markman) Outcomes:

• There is no public record of a Markman hearing or order in this specific district court case yet.

Discovery Milestones with Strategic Significance:

• A "REVISED STIPULATION TO" was filed on February 29, 2024, but the full content and strategic significance are not detailed in the available snippets.
• A Scheduling Order was issued on May 9, 2025.

Trial Events, Verdict, and Post-Trial Motions:

• The case has not reached the trial stage.

Settlement, Dismissal, Judgment, or Appeal:

• The case is active and has not yet reached a final disposition such as settlement, dismissal, or judgment.

Parallel PTAB IPR/PGR Proceedings:

• Microsoft Corporation has initiated inter partes review (IPR) proceedings against X1 Discovery, Inc. concerning patents related to the litigation.
  • IPR2025-00253: Microsoft Corporation filed a petition for IPR of claims 1-10 of U.S. Patent No. 7,370,035 B2. On July 22, 2025, the Patent Trial and Appeal Board (PTAB) instituted inter partes review, finding a reasonable likelihood that Microsoft would prevail in establishing the unpatentability of all challenged claims.
  • Microsoft is also concurrently challenging U.S. Patent No. 9,633,139 (IPR2025-00255) and U.S. Patent No. 10,552,490 (IPR2025-00254) in separate IPR proceedings. The '490 patent is the primary patent for this case summary. The IPR for the '490 patent (IPR2025-00254) is ongoing.
  • Patent Owner's (X1 Discovery's) Updated Mandatory Notices in the IPRs also identified U.S. Patent No. 8,498,977 as being asserted against Microsoft in the district court litigation.
  • The filing of these IPRs indicates a strategic move by Microsoft to challenge the validity of the asserted patents at the USPTO, which can often lead to stays in the district court litigation, though no explicit stay order has been found in the available information for 8:23-cv-02415.

The case remains active in the Central District of California, with the ongoing PTAB proceedings likely influencing its trajectory.

News and analysis coverage of X1 Discovery, Inc. v. Microsoft Corporation is limited, with most mentions coming from industry intelligence platforms rather than mainstream or dedicated legal news outlets.

RPX Empower reported on December 29, 2023, that X1 Discovery, Inc. accused Microsoft (Case No. 8:23-cv-02415) of infringing two search patents through its Microsoft Search feature in laptops preinstalled with Windows 10 or 11, as well as the Microsoft Windows 10, 11, and 365 operating systems and services. This report highlighted that the lawsuit against Microsoft appears to be part of a broader patent enforcement campaign by X1 Discovery, as the company also filed a complaint before the International Trade Commission (ITC) against Acer, ASUSTek, and Dell (337-TA-3714), targeting similar search functionality in certain laptops. Companion district court cases were also filed against Acer and ASUSTek in the Central District of California, and against Dell in the Western District of Texas. PatSnap also reported on June 9, 2026, about the transfer of the X1 Discovery v. Dell Technologies case from the Western District of Texas to the Central District of California, noting its stay pending the ITC proceeding.

While direct, in-depth articles on the X1 Discovery v. Microsoft case itself are not readily available, X1 Discovery's press releases and blog posts discuss their "AI In-Place" technology and its relevance to eDiscovery and enterprise search, often mentioning Microsoft 365 integration. For instance, X1 Discovery's website features articles from May 20, 2025, and June 16, 2026, highlighting the shift of law firms and major enterprises to X1 Search due to limitations of traditional enterprise search solutions, particularly with distributed platforms like Microsoft 365. These pieces, however, are promotional in nature and do not provide independent journalistic analysis of the ongoing litigation.

General patent litigation news and Microsoft-related legal developments in the press do not specifically focus on the X1 Discovery case. For example, articles discuss Microsoft's involvement in other class-action lawsuits related to securities fraud and AI product performance, or older patent cases that went to the Supreme Court. There is no reporting on specific damages sought or awarded, or any settlement terms in the X1 Discovery v. Microsoft litigation.

Sources

• rpxcorp.com
• patsnap.com
• x1.com
• x1.com
• globenewswire.com
• rosenlegal.com
• finnegan.com

Plaintiff X1 Discovery, Inc. is represented by a team of attorneys from Goodwin Procter LLP. The counsel includes both local California counsel and attorneys appearing pro hac vice from other Goodwin offices.

Here is a breakdown of the identified counsel:

• Natasha E. Daughtrey

  • Role: Local Counsel (Partner)
  • Firm & Office Location: Goodwin Procter LLP, Los Angeles, CA
  • Experience: Ms. Daughtrey is a partner in Goodwin's Intellectual Property Litigation practice and a member of the firm's Life Sciences Disputes group. She focuses on intellectual property litigation, including patent, trade secret, and trademark matters, and has experience with Hatch-Waxman and Biologics Price Competition and Innovation Act (BPCIA) litigation.

• I. Neel Chatterjee

  • Role: Local Counsel (Partner)
  • Firm & Office Location: Goodwin Procter LLP, Redwood City, CA
  • Experience: Mr. Chatterjee is a partner in Goodwin's Intellectual Property practice and serves on the firm's Executive Committee. He is recognized as a technology litigator and trial lawyer with substantial expertise in disputes related to patents, trade secrets, copyrights, and internet law.

• Patrick J. McCarthy

  • Role: Lead Counsel (Partner) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, Washington, D.C.
  • Experience: Mr. McCarthy is a partner in Goodwin's IP Litigation practice. He is a first-chair litigator with particular expertise in Section 337 investigations at the International Trade Commission (ITC) and regularly leads district court patent litigations, with an electrical engineering background.

• Christie L. Larochelle

  • Role: Of Counsel (Partner) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, Washington, D.C.
  • Experience: Ms. Larochelle is a partner in Goodwin's Intellectual Property Litigation practice, focusing on patent, trade secret, and trademark matters, and is a member of the firm's Life Sciences Disputes group. She holds a PhD in Physics and has experience representing clients in ITC and Hatch-Waxman patent infringement litigation.

• Kristin M. Beale

  • Role: Of Counsel (Associate) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, Washington, D.C.
  • Experience: Ms. Beale is an associate in Goodwin's Intellectual Property Litigation practice, concentrating on patent matters in biotechnology and pharmaceuticals. Her experience includes Hatch-Waxman litigation, other patent litigation, licensing disputes, and advising on complex life sciences patent disputes involving biologics and gene editing technologies.

• Emma L. Murray

  • Role: Of Counsel (Associate) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, Boston, MA
  • Experience: Ms. Murray is an associate in Goodwin's Litigation department and represents clients in intellectual property disputes, including patent litigation in district courts across the country, federal jury trials, and post-grant proceedings at the United States Patent and Trademark Office (USPTO). Her experience covers biotechnology, pharmaceutical, and medical device industries.

• Sravan K. Tumuluri

  • Role: Of Counsel (Associate) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, Washington, D.C.
  • Experience: Mr. Tumuluri is an associate in Goodwin's Intellectual Property Litigation practice. While specific details on his patent litigation experience were not extensively detailed in the provided search results, his inclusion on the First Amended Complaint for this patent infringement case indicates his involvement in the field.

• Jeremy D. Knight

  • Role: Of Counsel (Associate) (Pro Hac Vice)
  • Firm & Office Location: Goodwin Procter LLP, New York, NY
  • Experience: Mr. Knight is an associate at Goodwin Procter LLP, focusing his practice on intellectual property litigation, including patent, trademark, and copyright matters.

Microsoft Corporation is represented by external counsel, with appearances noted on the docket.

Here is a breakdown of the identified counsel for Microsoft:

• Christopher S. Marchese
  • Role: Counsel of Record
  • Firm & Office Location: Not explicitly stated in the provided snippets, but he is listed as counsel of record for Microsoft Corporation.
  • Experience: Mr. Marchese filed a G-123 Notice to appear as counsel of record for Microsoft Corporation on February 9, 2024.

Microsoft also employs a significant in-house legal team dedicated to intellectual property and patent litigation. While specific individuals from their in-house team may not have direct appearances on the district court docket, they play a crucial role in managing and strategizing the company's patent defense.

Notable Microsoft in-house counsel and their roles in patent litigation generally include:

• Lucky Vidmar

  • Role: Associate General Counsel and Head of IP Litigation
  • Firm & Office Location: Microsoft Corporation, Redmond, WA
  • Experience: Lucky Vidmar and his team manage Microsoft's docket of patent, trademark, copyright, and trade secret cases globally. Before joining Microsoft, he was a partner in the IP litigation group of Hogan Lovells.

• Cynthia Randall

  • Role: VP, Deputy General Counsel, and Head of Litigation
  • Firm & Office Location: Microsoft Corporation, Redmond, WA
  • Experience: Cynthia Randall oversees the defense of commercial and IP litigation, regulatory enforcement actions, and international arbitrations at Microsoft. She has over 30 years of complex litigation experience.

While not specifically listed as appearing in X1 Discovery v. Microsoft, other attorneys frequently represent Microsoft in patent litigation matters and may be involved behind the scenes or in related proceedings, such as the parallel PTAB IPRs. These include:

• Peter P. Chen

  • Role: Senior Counsel (co-head of Patent Office Trials group at Covington)
  • Firm & Office Location: Covington & Burling LLP, Palo Alto, CA
  • Experience: Specializes in intellectual property litigation and AIA trials before the PTAB, having served as a Lead Administrative Patent Judge at the PTAB. He has litigated over 75 patent cases.

• Betty Hong Chen

  • Role: Partner (Desmarais LLP)
  • Firm & Office Location: Desmarais LLP
  • Experience: Successfully defended Microsoft against patent claims brought by MediaPointe, leading to the invalidation of several patent claims and a summary judgment of non-infringement. She was recognized as a Daily Journal Top Intellectual Property Lawyer for 2025.

• Richard G. Gervase, Jr.

  • Role: Member (Mintz)
  • Firm & Office Location: Mintz, New York, NY
  • Experience: Advises clients on all aspects of intellectual property litigation, including patent, copyright, trademark, and trade secret litigation, and has represented numerous Fortune 100 companies in IP infringement cases. He was involved in Microsoft v. Motorola regarding standard essential patents.

• Robert C. Williams (sometimes referred to as Rob Williams)

  • Role: Partner (DLA Piper)
  • Firm & Office Location: DLA Piper
  • Experience: Concentrates on patent litigation in Federal District Courts, the ITC, and the USPTO, with experience in computer hardware, software, and wireless technologies. He has represented Microsoft in patent litigation involving touchscreen mobile devices and cloud-based graphics processing.