Rob Horwitz analyzes and writes about Microsoft licensing programs and product licensing rules. He also trains organizations on best Microsoft licensing practices.
Before co-founding Directions on Microsoft in 1992, Rob spent eight years at Microsoft in a variety of software development and technical marketing roles. He was a software developer on the first version of Macintosh Word and marketed Microsoft operating system- and server-based products while in the developer relations, networking product marketing, international, and OEM marketing groups.
Rob holds a B.S. in computer science from the Massachusetts Institute of Technology and an M.B.A. from Wharton.
Latest Content by Rob Horwitz
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May 1, 2026 · by Rob Horwitz
Windows Enterprise Rights Flowchart
Illustrates the ways an organization can acquire the right to install and run Windows Enterprise edition locally on an end-user’s...
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May 1, 2026 · by Rob Horwitz
Per Core License Model Flowchart
Explains how to calculate the number of core licenses required for SQL Server (versions 2025 / 2022 / 2019 /...
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May 1, 2026 · by Rob Horwitz
Windows client OS edition packaging
Compares technical feature and use right differences across Windows 10 /11 Pro, Windows 10 / 11 Enterprise Per Device, and...
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May 1, 2026 · by Rob Horwitz
SQL Server Edition Packaging
Compares SQL Server edition features across versions 2025, 2022, 2019, 2017, 2016, and 2014.
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May 1, 2026 · by Rob Horwitz
Windows Server Edition Packaging
Diagram compares Windows Server Standard and Datacenter edition features across versions 2025, 2022, 2019, and 2016.
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April 23, 2026 · by Rob Horwitz
Teams-related Product Packaging
Maps Teams-related license types (most Teams-branded) to the AI, collaboration, and management/security capabilities, as well as client-side device support, they...
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April 17, 2026 · by Rob Horwitz
CAL Suite Contents
Outlines the components currently in the Core CAL Suite and Enterprise CAL Suite.
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April 17, 2026 · by Rob Horwitz
CALs Included with Online Services Suites
Enumerates the CAL (client access license) and Client ML (Management License) subscriptions included with Microsoft 365, Office 365, and Enterprise...
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Updated: April 17, 2026 · by Rob Horwitz
External User Qualification Requirements
Explains the criteria a contractor or agent working on behalf of an organization licensing Microsoft software must meet for the...
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April 17, 2026 · by Rob Horwitz
Enterprise Agreement Contract Stack
The interconnecting legal documents that form what is commonly thought of as an “Enterprise Agreement contract.”