Microsoft's Browser Patent — At the Center of the Biggest Antitrust Case in Tech
Microsoft's 1998 browser patent covers the integration of Internet Explorer into Windows — the technical mechanism that was at the heart of the United States v. Microsoft antitrust case, the most consequential legal action against a technology company in history.
Original patent title: “Distributed hypermedia method for automatically invoking external application providing interaction and display of embedded objects within a hypermedia document”
What this patent covers
The actual claim
This patent describes a method for deeply integrating a web browser into an operating system such that browser capabilities are available system-wide, not just when the browser application is running. Specifically, it covers a technique where HTML rendering and web navigation functionality are provided as reusable system components (COM objects) that any application can call — including Windows Explorer's file browsing interface. This made it possible for Windows to render local files as web pages, for applications to embed web content without launching a separate browser, and for the browser to share system resources with the OS rather than running as a fully separate application.
What this patent does NOT cover
The boundaries
- The Internet Explorer browser's user interface — the patent covers the system integration architecture, not the visual design
- Browser security sandboxing — later security features that isolate browser content from the OS are separate
- JavaScript engines — the ECMAScript/JScript engines are different IP
- Web standards implementation — the specific HTML, CSS, and DOM implementations are separate from this integration architecture
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
Microsoft's strategy — bundling Internet Explorer with Windows for free and integrating it deeply into the OS — destroyed Netscape, which had been selling its Navigator browser for $49. The technical integration made IE faster (sharing OS resources) and ubiquitous (on every Windows PC). But the DOJ argued this was not a technical innovation for users' benefit — it was weaponization of the Windows monopoly to foreclose a competitor. Judge Thomas Penfield Jackson agreed, ruling in 2000 that Microsoft had illegally maintained its monopoly and ordering the company broken into two parts. An appeals court overturned the breakup order but affirmed the monopoly finding; Microsoft eventually settled with the DOJ, agreeing to share Windows APIs with third parties.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Internet Explorer's market share went from near-zero in 1995 to over 95% by 2002, entirely on the strength of Windows bundling — Netscape Navigator declined from 90% to less than 5% in the same period
The antitrust settlement required Microsoft to share Windows APIs with third-party browser makers — which indirectly enabled Firefox (2004) and later Chrome (2008) to compete on Windows
The European Commission fined Microsoft €497 million in 2004 for browser bundling and required it to offer a 'browser ballot screen' in Windows in Europe — users could choose their browser at setup
Why it matters
The bigger picture
United States v. Microsoft (1998–2001) was the most significant antitrust action against a technology company until the current generation of cases against Google, Meta, and Amazon. It established that network effects and platform control could constitute illegal monopoly maintenance even without predatory pricing. Microsoft's settlement — widely considered inadequate — left the Windows monopoly intact but opened the API ecosystem enough for alternative browsers to survive. The case's legacy is directly visible in today's antitrust scrutiny of Apple's App Store and Google's search defaults: the same legal theories developed in U.S. v. Microsoft are now being applied to the next generation of platform controllers.
Filed
October 17, 1994
Granted
November 17, 1998
Claim 1 — Plain English
What this patent covers
This patent describes a method for deeply integrating a web browser into an operating system such that browser capabilities are available system-wide, not just when the browser application is running. Specifically, it covers a technique where HTML rendering and web navigation functionality are provided as reusable system components (COM objects) that any application can call — including Windows Explorer's file browsing interface. This made it possible for Windows to render local files as web pages, for applications to embed web content without launching a separate browser, and for the browser to share system resources with the OS rather than running as a fully separate application.
The clever bit
Microsoft's strategy — bundling Internet Explorer with Windows for free and integrating it deeply into the OS — destroyed Netscape, which had been selling its Navigator browser for $49. The technical integration made IE faster (sharing OS resources) and ubiquitous (on every Windows PC). But the DOJ argued this was not a technical innovation for users' benefit — it was weaponization of the Windows monopoly to foreclose a competitor. Judge Thomas Penfield Jackson agreed, ruling in 2000 that Microsoft had illegally maintained its monopoly and ordering the company broken into two parts. An appeals court overturned the breakup order but affirmed the monopoly finding; Microsoft eventually settled with the DOJ, agreeing to share Windows APIs with third parties.
What it does not cover
- The Internet Explorer browser's user interface — the patent covers the system integration architecture, not the visual design
- Browser security sandboxing — later security features that isolate browser content from the OS are separate
- JavaScript engines — the ECMAScript/JScript engines are different IP
- Web standards implementation — the specific HTML, CSS, and DOM implementations are separate from this integration architecture
Patent Journey
From filing to expiry
Patent Filed
1994
Patent Granted
1998 · 4yr after filing
Highly Cited
577 patents cite this
Patent Expired
2014
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
8/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assignee
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
The original legal language
Original claims
12 claims as filed with the patent office.
Glossary
Key terms defined
- browser bundling
- Including a web browser with the operating system at no extra charge — the practice at the center of the antitrust case
- monopoly maintenance
- The antitrust concept that a company with market power illegally acts to preserve that power — the finding against Microsoft
- COM (Component Object Model)
- Microsoft's software architecture for reusable system components — Internet Explorer was integrated into Windows as a COM object, making browser functionality available to all applications
Citations
Patent lineage
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 12564871 · 2026
A Fixture for Cleaning Showerheads with Multiple Separate Chambers
This patent describes a cleaning device for showerheads that uses a fixture with three or more separate internal compartments and channels to direct cleaning fluid to the showerhead's upper surfaces.
ASM IP HOLDING BV
US 12324579 · 2025
Surgical Stapler Battery Health Check During Operation
This patent describes a powered surgical stapler that can detect if some of its rechargeable battery cells are damaged while it's actually firing staples, helping ensure the procedure finishes safely.
CILAG GMBH INT
US 12471982 · 2025
Surgical Tool That Combines Energy Treatment and Stapling
CILAG's patent details a surgical instrument that applies therapeutic energy to tissue, monitors its properties, then deploys staples, adapting the stapling based on the initial energy treatment and monitoring.
CILAG GMBH INT
US 11918209 · 2024
Real-Time Surgical Instrument Status on Live Video During Operations
This patent describes a surgical system that shows live video from inside the body and overlays important information about the surgical tool directly onto the screen, helping surgeons operate more precisely.
CILAG GMBH INT
US 8697359 · 2014
How to Use CRISPR-Cas9 to Edit Genes in Human Cells
This patent describes a method and system for precisely altering gene expression in eukaryotic cells, including human cells, using an engineered CRISPR-Cas9 system that targets and cleaves specific DNA sequences.
Massachusetts Institute of Technology
US 4683195 · 1987
How to Make Many Copies of a Specific DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a fundamental process for making millions of copies of a specific DNA or RNA segment from a tiny sample, enabling its detection.
Cetus Corp
Semantically similar
You might also find these interesting
US 5347632 · 1994 · Prodigy Services Co
How Early Online Services Delivered Applications Using Networked 'Objects'
US 5774670 · 1998 · Netscape Communications Corp
The HTTP Cookie — How Websites Remember Who You Are
US 5960411 · 1999 · Amazon com Inc
How Amazon's One-Click Online Ordering System Works
US 6285999 · 2001 · Leland Stanford Junior University
How Websites Get Ranked by Who Links to Them
Patent monitoring