Larry Masinter

Larry Masinter

Blog: Masinter's Musing

  • Summary

Most publications and activities are listed here. See LinkedIn profile for more details.


I'm interested in consulting about things I know about, most of which is reflected in these pages.

Things I've been working on lately are

  • restoring Interlisp-D to usability (as a kind of Vintage Software), to recapture the sense of fluidity in the development cycle that I've not encountered since, perhaps as part of the Computer History Museum and/or the Internet Archive.
  • Long-term archiving of documents, including my own. If we are going to live in an all-digital world, we have to have a way of keeping documents for hundreds of years with little risk of undetected alteration. This is work I started many years ago.
  • Internationalization of URLs is not a solved problem, and the problem is exacerbated by the poor attention to URLs in those developing Unicode for domain names. This is work I tried to get going 10 years ago, but failed to get enough participation in the IETF. Maybe ICANN or Unicode Consortium could help.
  • A better foundation for a theory of the semantic web: treating belief as the foundation, modeling trust as an inclination to beleve assertions of the trusted party. Move away from denotation semantics and a possible worlds model to one based on Shannon-style information theory.
  • The nature of the evolution of Standards vs. evolution of Open Source, depending on the authority of the ownership of well-known names like "http" or "GET".
  • Explaining the jokes of RFC 2324, HTCPCP (The "HyperText Coffee Pot Control Protocol), and what exactly I was poking fun at.
  • Working on Open Data with or without PDF.
  • Internet Standards

A good chunk of my career has been around Standards, especially (but not exclusively) for the Web. I would explain my job as "arguing about how the Internet should work".

File Formats

What is a file format? A lot of my work has been in defining file formats, standards around them, protocols for negotiating formats for subsequent communication.


PDF, the Portable Document Format, was invented by Adobe folks more than 25 years ago--older than the web. Perhaps there are things we'd design differently today, but PDF is solid, widely deployed, and actively maintained. For some purposes, there's nothing like it. I'm helping with some related efforts:

  • PDF and Open Data W3C Community Group established to document "best practices" for making data in PDF more accessible to simple processing using readily available tools.
  • RFC8118: updated the registration of "application/pdf" primarily to show the "owner" is now ISO (International Standards Organization) and not Adobe. (also see GitHub repo).
  • RFC7995: PDF Format for RFCs: The IETF is moving (slowly) to change its document format(s); IETF specs will be published in PDF and HTML (and XML), not just plain text. Note that the PDF file will include the XML as an attachment.

Metadata in Files

Metadata is data about data: e.g., for a phone call, who called whom when; for a library book, the card catalog information. There are different kinds of metadata, and different ways of associating metadata with the data it describes.


Forms are an interesting component of file formats because they imply a request for information, and span the gap between User Interface and API.

File Formats and Content Negotiation


The main invention of the web: using URLs for hypertext. You'd think the standards for URLs would be simple, but this fundamental part of he web still has problems.

  • (2015) URL problem statement and directions
  • (2015) Guidelines and Registration Procedures for New URI Schemes.
  • (2011) masinter-dated-uri The "tdb" and "duri" URI schemes.
  • (2010) ietf-iri-3987bis Internationalized Resource Identifiers (IRIs), in IRI working group (abandoned)
  • RFC 6068 "The 'mailto' URI Scheme", M. Duerst, L. Masinter, J. Zawinski, 2010.
  • RFC 4395 "Guidelines and Registration Procedures for New URI Schemes", Tony Hansen, Ted Hardie, Larry Masinter, 2006.
  • RFC 3986 "Uniform Resource Identifier (URI): Generic Syntax", Tim Berners-Lee, Roy Fielding, Larry Masinter, 2005.
  • RFC 3553 "An IETF URN Sub-namespace for Registered Protocol Parameters." Michael Mealling, Larry Masinter, Ted Hardie, Graham Klyne, 2003.
  • (until 1995) chair URI working group, defining standards for locating, naming, and describing resources on the Internet.
  • RFC 2972 "Context and Goals for Common Name Resolution", N. Popp, M. Mealling, L. Masinter, K. Sollins,z 2000. Who owns a name? At the time, I was also on the technical advisory board of RealNames.
  • RFC 2732 "Format for Literal IPv6 Addresses in URL's", R. Hinden, B. Carpenter, L. Masinter. December 1999.
  • RFC 2718 "Guidelines for new URL Schemes". L. Masinter, H. Alvestrand, D. Zigmond, R. Petke. November 1999
  • (1999 talk) Problems URIs don't solve. Presentation at TWIST 99, The Workshop on Internet-scale Software Technologies, Internet Scale Naming.
  • RFC 2397 "The 'data' URL scheme." L. Masinter. August, 1998.
  • RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax." T. Berners-Lee, R. Fielding, L. Masinter, August 1998.
  • RFC 2368 "The mailto URL scheme." P. Hoffman, L. Masinter, J. Zawinski. July, 1998.
  • RFC 1738 "Uniform Resource Locators (URL)." T. Berners-Lee, L. Masinter & M. McCahill. 1994.
  • RFC 1737 "Functional Requirements for Uniform Resource Names." K. Sollins & L. Masinter. 1994.
  • HTTP
The primary way communication happens for the Web and many other applications:
  • (2015) HTTPbis working group, trying to guide what happens after HTTP/2.
  • (2012) HTTP: how we got here and where we should go, comments for HTTPbis working group at IETF 70, Vancouver, BC, Canada.
  • (until 2000) chair HTTP working group which developed RFC 2616 HTTP/1.1, which improved the performance and reliability of the web significantly.
  • (2000 talk) Issues using HTTP in Protocols, at Open meeting on XML in protocols.
  • (2000 talk) HTTP Extensions (risks of reusing HTTP for non-web functions)
  • RFC 2616 "Hypertext Transfer Protocol -- HTTP/1.1" R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach, T. Berners-Lee. 1999.
  • (1998/3/1) RFC 2324 "Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)." An April 1 joke with a serious purpose -- to spoof ways in which HTTP had been extended inappropriately.

Standards Organizations & Processes

Computers around the world from different origins work with each other because everyone agrees how they should work. There's not a separate Internet for Google, Microsoft, Amazon, Adobe. But of course not everyone agrees; working out differences about the future is standards work.

Governance and the Internet

The primary value of the Internet comes from the fact there is only one, with everyone (and everything) connected. Governance (regulation, legislation) is local and hierarchical: city, state, region, country, with interactions relegated to treaties, negotiation, or worse (think "military"). How can anyone offer a global service and be subject to every constraint of every jurisdiction?


Other standards

Sometimes things don't work out or have more narrow applicability than expected.
  • (1996) WebDAV working group
  • RFC 2542 "Terminology and Goals for Internet Fax." L. Masinter. 1999.
  • RFC 2534 "Media Features for Display, Print, and Fax." L. Masinter, D. Wing, A. Mutz, K. Holtman. 1999.
  • RFC 2532 "Extended Facsimile Using Internet Mail." L. Masinter, D. Wing. 1999.
  • Internet Printing

Web history

Philosophy, semantics

Other topics

Cloud services

  • (1997) 20 years ago (at Xerox), I led a '' project which proposed a Software as a Service offering; see presentation. Any earlier 'clouds'? The important part was the plan to charge per 'click' (microservice), in the same way that Xerox made money per-page (selling supplies and service).

Internet of Things

  • Digital preservation

How do you save documents for a long time? Life insurance policies, plans for buildings, personal health records.

  • Interlisp
Through around 1986 I worked on an evolving code base for Interlisp, a software development environment for Lisp programming, written in Lisp.

Common Lisp

  • Artificial Intelligence
  • Other links