Network Working Group                                      H. Tschofenig
Internet-Draft                                    Nokia Siemens Networks
Intended status: Informational                                  B. Aboba
Expires: November 10, 2012                         Microsoft Corporation
                                                             J. Peterson
                                                           NeuStar, Inc.
                                                            D. McPherson
                                                             May 9, 2012

   Trends in Web Applications and the Implications on Standardization


   Advancements in the design of web browsers have introduced
   fundamental changes to the architecture of application protocols.
   The widespread availability and growing sophistication of JavaScript
   interpreters in browsers enables web servers to push to browsers all
   of the application logic required to implement a client-server
   protocol.  Consequently, many client-server applications that once
   required an installed client on a host computer now can rely simply
   on a modern browser to act as a client for the purposes of a
   particular application.  For example, where once email clients
   required a custom application to access an inbox, increasingly a web
   browser can serve this purpose as well as the purpose-built
   applications of the past.  Similarly, HTTP with the assistance of
   JavaScript can subsume the functions performed by the protocols like
   POP3 and IMAP.  The need for Internet standards beyond HTTP to
   implement an email inbox application consequently diminishes - why
   author standards and worry about interoperability of clients and
   servers when the server can simply push to the client all the code it
   needs to be interoperable?

   Many client-server applications on the Internet could potential
   migrate to this code distribution methodology.

   [Note: A separate mailing list has been created for discussions
   related to this document and it can be found here: ]

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering

Tschofenig, et al.      Expires November 10, 2012               [Page 1]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 10, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   ( in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Tschofenig, et al.      Expires November 10, 2012               [Page 2]

Internet-Draft  Web Applications: Trends and Implications       May 2012

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Impact for the Standardization Community . . . . . . . . . . .  6
   3.  Limitations of Mobile Code Distribution  . . . . . . . . . . .  9
     3.1.  Performance Limitations  . . . . . . . . . . . . . . . . .  9
     3.2.  Transport Protocol Limitations . . . . . . . . . . . . . . 10
     3.3.  Security, Privacy, and Cryptographic Processing
           Limitations  . . . . . . . . . . . . . . . . . . . . . . . 11
     3.4.  Source Code Hiding Limitations . . . . . . . . . . . . . . 12
   4.  Recommendations  . . . . . . . . . . . . . . . . . . . . . . . 13
   5.  Conclusions  . . . . . . . . . . . . . . . . . . . . . . . . . 14
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 16
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 17
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
   9.  Informative References . . . . . . . . . . . . . . . . . . . . 19
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22

Tschofenig, et al.      Expires November 10, 2012               [Page 3]

Internet-Draft  Web Applications: Trends and Implications       May 2012

1.  Introduction

   The generic nature of the personal computer has enabled application
   providers to write general purpose programs and to make it available
   for download.  This flexibility has lead to lots of innovation on the
   Internet but has also introduced security challenges since it is
   difficult for end users to judge the trustworthiness of downloaded
   programs in any reasonable way.  Consequently, many users are very
   suspicious about any download they are asked to accept.  An important
   goal of those deploying applications is to reach a widespread
   deployment as fast as possible and to react to changing needs as
   quickly as possible, which to a large extent requires the ability to
   continously update code on end devices.  With operating system
   updates happening less frequently and the acceptance for software
   downloads decreasing the browser was seen by many as an ideal
   platform for dynamically downloaded running code.  JavaScript was
   initially perceived as being quite limited in functionality but has
   been supported by all browsers.  This perception has changed over the
   last couple of years when it became the scripting language
   implemented in the majority of browsers, also referred as the
   'assembly language of the Internet'.

   For application developers writing code running on Web servers as
   well as for applications that are downloaded to the end device the
   desire was always to develop the application once without having to
   consider all the different runtimes (operating systems or browsers).
   Now, with the PC and the cellular phone segments getting increasingly
   blurry this desire is stronger than ever considering the increased
   number of obstacles that have to be dealt with.  For example, it is
   highly unlikely that an application will work on various different
   devices even if all the devices were produced by a single mobile
   phone vendor.  Getting users to download new applications, and to
   install software updates also leaves software developers in a
   difficult situation.

   How can software be developed so that it can (1) be updated instantly
   when a new version becomes available, (2) be used across a wide range
   of devices, and (3) be as powerful as regular desktop applications?
   This sounds almost impossible but with the increased capabilities of
   Web browsers, and JavaScript in particular, it seems that the
   Internet community has gotten a couple of steps closer to achieve
   this goal.

   This document describes these developments, highlights impacts for
   the standardization community, and provides recommendations for those
   developing applications.

   Note that the writeup heavily refers to JavaScript as a mechanism for

Tschofenig, et al.      Expires November 10, 2012               [Page 4]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   mobile code distribution.  There is, however, nothing special about
   JavaScript as a language by itself and it may well be possible that
   other languages will be developed for usage in other environments
   offering similar or even superior capabilities.

Tschofenig, et al.      Expires November 10, 2012               [Page 5]

Internet-Draft  Web Applications: Trends and Implications       May 2012

2.  Impact for the Standardization Community

   In the application area communication protocols often follow the
   pattern where an end host utilizes some application service provider
   for communication setup and sometimes also for message routing
   towards the other communication end point.  Examples of such a
   standardized communication protocols are the Post Office Protocol
   (POP) [1], the Internet Message Access Protocol (IMAP) [2], as well
   as the Session Initiation Protocol (SIP) [3] and the Extensible
   Messaging and Presence Protocol (XMPP) [4].

   Figure 1 shows a typical scenario where two hosts, Alice and Bob,
   interact with an application provider.  A desired interoperability
   goal often has been to let a software vendor develop the software
   clients at the end hosts to interact with a random application
   provider offering the specific protocol implementation.

             |               |
             |  Application  |
             |  Service      |
             |  Provice      |
             |  |
                 _,   .
               ,'      `.
            _,'          `.
          ,'               `._
        -'                    -
     ,''''''''|           ,''''''''|
     |  End   |           |  End   |
     |  Host  |           |  Host  |
     |  Alice |           |  Bob   |
     |........'           |........'

           Figure 1: Communication Partners from a Single Domain

   Many protocols developed in the IETF also offer the ability to let
   users from different application service providers (via their end
   hosts) to communicate.  Figure 2 shows this architecture graphically,
   where additional interoperability needs are created between the
   application service provider domains.

Tschofenig, et al.      Expires November 10, 2012               [Page 6]

Internet-Draft  Web Applications: Trends and Implications       May 2012

              .................              .................
              |               |              |               |
              |  Application  |              |  Application  |
              |  Service      |--------------|  Service      |
              |  Provider     |              |  Provider     |
              |  |              |  |
              |_______________|              |_______________|
                  _,                                .
                ,'                                   `.
             _,'                                       `.
           ,'                                            `._
         -'                                                 -
      ,''''''''|                                        ,''''''''|
      |  End   |                                        |  End   |
      |  Host  |                                        |  Host  |
      |  Alice |                                        |  Bob   |
      |........'                                        |........'

          Figure 2: Communication Partners from Multiple Domains

   These two figures did not make the attempt to differentiate signaling
   message exchanges from the actual data traffic exchange.  The data
   traffic may be exchanged directly between the end hosts themselves
   and therefore creates additional interoperability requirements when
   those software clients shall be developed by independent parties.

   While many standardization efforts in the IETF have considered the
   possibility for using proprietary protocols along the end host to
   application service provider leg, this has usually been considered as
   exception or a transition case.  It is typically assumed that the
   desired end state of standardization is to move from a proprietary
   protocol to the standardized alternative in the long run, which
   allows client software vendors to interact with all forms of
   application service providers.  Such an approach increases the need
   for standardization and requires far more interoperable network
   elements to exist.

   With a mobile code distribution platform as the Web with JavaScript
   offers it is possible to leave the end host to application service
   provider interaction largely non-standardized.  Only very few
   standardization actions are required, to for example, enhance the
   capability of JavaScript to perform additional functions, such as the
   access to underlying hardware functions (e.g., microphone, GPS module
   or a camera).

   Quite clearly applications can be designed in a way that fewer
   standardized client-server protocols are needed.  The question
   therefore remains for those actively pursuing standardization as to

Tschofenig, et al.      Expires November 10, 2012               [Page 7]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   where the limitations of the JavaScript-based mobile code
   distribution approach is.  Section 3 tries to explore this aspect in
   more detail.

Tschofenig, et al.      Expires November 10, 2012               [Page 8]

Internet-Draft  Web Applications: Trends and Implications       May 2012

3.  Limitations of Mobile Code Distribution

   The usage of JavaScript is, however, not always the right choice for
   application developers and even though a number of new building
   blocks are being made available, such as HTML5 [5] and various
   JavaScript extensions, there are still a number of limitations in
   today's browser environment.  We list a couple of those challenges,
   some of which will be resolved in the near future as standardization
   and deployment progresses, while others will remain a challenge for a
   long time.

3.1.  Performance Limitations

   Early JavaScript implementations did not offer high performance.
   Over many years very little attention was paid to boost the
   performance until recently when the Google JavaScript engine V8 [6]
   started to compile JavaScript code directly into machine code when it
   is first executed.  More details about the design can be found at

   A more serious limitation is the graphics capabilities in browsers.
   Efforts are under way to enhance the API capabilities, for example
   WebGL [8] bringing 3D graphics to the browser with features similar
   to OpenGL ES 2.0 that can be used in HTML5 canvas elements but
   expensive computations on the end host need to migrate from the
   Central Processing Unit (CPU) to the Graphics Processing Unit (GPU)
   for proper performance.  Simple 3D games (similar to the recently
   demonstrated Quake II port to HTML5 [9] utilizing JavaScript, the
   WebSocket API [10] and the Web Storage API [11]) can now be
   implemented but state-of-the-art games and virtual worlds are out of
   reach.  The problem is with the number of polygons that many games
   and virtual worlds need to process and display.  Games, like Quake,
   use a limited number of textures, and the complexity of the scene
   graph is small.

   In comparison to virtual worlds where the content is put together by
   users, in many games the playing field is carefully designed by
   experts.  This has implications for the complexity of the scene
   graph.  On the other hand, most virtual worlds do not rely on rapid
   communication updates in the same way that many action and tactic
   games do.  Joshua Bell illustrated this with an example of 'a quiet
   scene with a single user running around in SecondLife [12].  A
   teleport to a region can easily have a scene graph with 2000 nodes, a
   couple hundred 3D textures, 4000 vertexes, and 20 MByte of vertex
   data.  This corresponds to the maximum a graphics developer would
   typically like to have in a state-of-the-art game.  In a busy scene
   with lot of user generated content and avatars the volume easily
   jumps up by a factor of five.' [13].  The size of the game itself

Tschofenig, et al.      Expires November 10, 2012               [Page 9]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   (often due to the high quality textures) and software updates is
   impressive; often reaching beyond several 100 Mbytes.  Utilizing
   persistent storage and caching in combination with more aggressive
   client-server interactions demands a different style of programming
   and therefore also puts different constraints on the protocol design.
   This might also stress the current Mbyte limits for Web storage.

   Initial work to deal with more sophisticated graphics computation has
   started already, as described in the recently published article [14]
   about elevating JavaScript performance through offloading processing
   to the GPU.  As stated in the announcement of the Jetpack 0.5 contest
   [15]: 'By giving webpages and add-ons easy access to the raw
   processing power available on most computers, the range of abilities
   that the web can have greatly increases.'.

3.2.  Transport Protocol Limitations

   In [16] Jonathan Rosenberg argued that the new waist of the Internet
   hourglass is UDP and TCP, rather than IP as in the initial design.
   Today, application protocol designers may, however, get the
   impression that tunneling inside HTTP or even HTTPS is required to
   get an application running in a large number of environments,
   especially to reach a customer base that is connected to the Internet
   through an enterprise network.  Needless to say that more complex
   tunneling leads to more complexity, the data transport adds overhead
   and the initial environment sensing phase adds delays.  This is
   certainly true for the VoIP context where the payload data is
   comparatively small to the overall header size (including the TCP/
   HTTP headers).  The work on Interactive Connectivity Establishment
   (ICE) [17] is relevant for the sensing phase and this functionality
   may need to be replicated in the browser environment.  For this
   purpose it is more and more common to limit the number of individual
   connections and to instead multiplex them over a single transport
   connection.  See, for example, SPDY [18] and developments in the VoIP
   context [19].  Worse than inefficiency is that some real-time
   applications do not behave well with the retransmission behavior of
   TCP.  For real-time voice and video applications, for virtual worlds,
   and for many games it is acceptable to loose video and voice frames
   from time to time without waiting for retransmission.

   Adding the support for UDP to browsers again adds complexity, as the
   experience with Voice over IP showed, particularly when the protocols
   are not multiplexed together, so that it is necessary to identify
   multiple working end-to-end paths for the traversal of Network
   Address Translators (NATs) and firewalls.  With the transition to
   IPv6 the number of NATs is likely to increase.  Furthermore, in many
   cases it might be desired to perform route optimization for data
   traffic and to exchange it directly between the two endpoints

Tschofenig, et al.      Expires November 10, 2012              [Page 10]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   whenever possible to reduce the financial costs and the added delay
   of using an anchor point.  For example, Google Talk only requires the
   involvement of relays for 8% of their calls, as reported in [20] by
   utilizing ICE.

   It should be noted that audio and video streaming capabilities have
   been available in the browser for a while with plug-in support.  More
   sophisticated audio support, such as tagging audio with x/y positions
   for 3D audio, is not even possible with the Adobe Flash application
   today.  The challenge with video support in browsers is based on the
   lack of universal support of a specific video codec.  The lack of
   hardware support is secondary although relevant for increased
   performance and lower energy consumption.  Naturally, supporting
   different codecs makes the work of web developers and content
   distributors difficult.

3.3.  Security, Privacy, and Cryptographic Processing Limitations

   Many protocol mechanisms have several built-in cryptographic
   primitives and and the same capabilities must be available in the
   browser in order to migrate applications that use these capabilities.
   For example, JavaScript allows cryptographic operations to be
   implemented (see [21] for a JavaScript AES or other cryptographic
   functions [22] implementation) but access to hardware crypto-
   processors, smart cards [23] or to key storages from JavaScript is
   still at an early stage and, at the time of writing, not available as
   a standardized JavaScript API.

   The security model of JavaScript is different than the one offered by
   Widgets [24] (available with different platforms/operating systems,
   such as Mac OS X (via the dashboard), Windows 7, Opera, etc.) or
   classical operating systems.  JavaScript code does not declare what
   operations it is intended to perform.  Even with Widgets there is the
   question of who verifies any of these privileges.  It can hardly be
   assumed that the end user will be bothered with such a responsibility
   (due to the lack of his or her expertise.  Furthermore, the semantic
   of end-to-end security is challenged when the distinct communication
   legs support protocols with different semantics, and dissimilar
   encodings.  Imagine a browser that sends location data encoded in
   JSON [25], for example using [26], to a web server, which converts it
   to XML, for example into the PIDF-LO format [27] to interoperate with
   another application service provider.  Consequently, this server then
   uses XMPP to deliver notifications to its users, for example using
   [28].  No two of these encodings offer the same privacy mechanisms
   nor security properties.

   The privacy implications of a heavily JavaScript-centered Web
   environment are not yet well understood.  For example, the SIP

Tschofenig, et al.      Expires November 10, 2012              [Page 11]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   privacy mechanisms, described in [29], [30], and [31]) rely to a
   large degree on the end point to select independent RTP/SRTP relays,
   and to obfuscate important header fields based on the context
   provided by the user.  One could argue that these standardized SIP
   privacy extensions represent a community design even though those who
   deploy ultimately make the final decisions about what policies to
   use.  When the executable code itself is provided by the application
   service provider then the privacy functionality for data minimization
   can change at any point in time with little possibility that the user
   will notice.  Only the application service provider makes decisions
   about what functionality it desires without having to consult or
   agree with anyone else.

3.4.  Source Code Hiding Limitations

   In many commercial environments it is not desirable to make source
   code available to the public.  With JavaScript the source code is
   sent from the server to the browser and only compression and
   obfuscation tools are available [32].  However, the only way to
   protect code is to not expose it to observers, instead leaving the
   important code on the server-side and have a minimal public
   Javascript code segment use asynchronous message exchanges with the

Tschofenig, et al.      Expires November 10, 2012              [Page 12]

Internet-Draft  Web Applications: Trends and Implications       May 2012

4.  Recommendations

   This section lists a few basic questions for protocol authors.  We
   hope that in answering these questions honestly a thought process
   will be triggered that may lead you to re-consider your design before
   starting the standardization effort that may not lead to successful
   deployment.  Note: We use the term 'protocol' below to refer to a
   protocol extension, a single protocol, or to a complete protocol
   suite, or an entire architecture.

   1.  Does your standardization effort fall priminarily into the
       client-to-server interaction described in this document?  If the
       answer is "yes", is there a story how the involved stakeholders
       can innovate at a high speed?

   2.  Are you attempting to offer functionality typically found at the
       application layer at the lower layers?  If so, have you carefully
       investigated the cost vs. benefit tradeoff?

   3.  Does your protocol design involve other stakeholders whoes goals
       are either not known or potentially not aligned with the goals of
       your envisioned deployment, i.e. for successful deployment do you
       require cooperation of stakeholders who may have disincentives
       (or unclear incentives) to deploy your protocol?

   4.  When designing your protocol have you considered the Web
       application environment?  Do you understand Web development
       yourself or do you have experts from the Web development
       community involved in your work?

   5.  Does your protocol design offer the ability to carry payloads on

   6.  Why is the current Web framework unable to meet your application
       requirements?  Have you documented the reasons?

   7.  Have you implemented your protocol in a tyipcal Web development
       programming language?  Hands-on experience may help you to detect
       problems with using your application design in a Web context in
       early stages of the design.

   8.  Is your protocol deployed already?  If not, who do you envision
       to implement and deploy it?

Tschofenig, et al.      Expires November 10, 2012              [Page 13]

Internet-Draft  Web Applications: Trends and Implications       May 2012

5.  Conclusions

   This document aims to highlight recent trends in Web application
   development with impact to Internet standardization.  In a nutshell,
   there is a certain class of applications for which the
   standardization need is diminishing: chances are good that your
   standardization work will not be relevant relevant in such an

   A lot of this change is driven by mobile code distribution using
   JavaScript executed on the end host (typically in the Web browser)
   while server-to-server communication is not yet impacted.

      We are, however, already seeing server-side JavaScript
      implementations.  NodeJS [33] is such an example that is built on
      top of the V8 JavaScript engine.  It runs multiple concurrent
      JavaScript execution engines in one thread allowing to develop a
      massively concurrent Web server in JavaScript, addressing a
      typical pain point for server developers when implementing
      distributed systems.  As another example, CommonJS [34] defines
      APIs that handle many common application needs, including those
      that go beyond the usage in Web browsers (such as regular command
      line programs).

   Hence, just as the barriers for rapidly deploying code have dropped
   on the client side; the server side will likely follow.

   Even if there are challenges for standardization there are other
   areas where work is needed:

   o  The development of of protocol mechanisms to support a larger
      range of applications will have an important role to play in the
      future.  Examples of such efforts include the currenly ongoing
      work on 'BiDirectional or Server-Initiated HTTP' in the HYBI
      working group [35].  For future work on improving the performance
      of the Web, for example [36], improvements in HTTP, or common
      security functionality for the Web as standardized in the Web
      Security working group [37].

   o  In those areas where application islands want to interact with
      larger eco-systems the need for cross-domain communication arises.
      Often, this is done in a proprietary way but for larger
      distributed systems and for common functions standardized
      solutions are valuable.  This can be observed today within the
      VoIP environment, although much slower than expected, in the case
      of Voice over IP peering but also in the Internet identity
      management community under the umbrella of 'data portability'
      [38].  As recent IETF work in this area the Open Authentication

Tschofenig, et al.      Expires November 10, 2012              [Page 14]

Internet-Draft  Web Applications: Trends and Implications       May 2012

      Protocol (oauth) [39] working group could be referenced.  OAuth
      deals with more sophisticated security protocol interactions that
      require multiple parties to participate in an interoperable way.

   o  Everyone knows that protocol design is hard regardless whether it
      happens inside a standards developing organization, like the IETF
      or W3C, or in some other less structured community.  For Web
      developers the standardization results are often only visible if
      they appear in form of rich JavaScript libraries and development
      frameworks, such as JQuery [40], the Prototype JavaScript
      Framework [41], MooTools [42], YUI [43] and Narwahl [44].  In
      order to have an impact in the Web community it is essential for
      working groups participants to think about how to their protocols
      can be deployed in a Web environment, for by making JavaScript
      implementations available.  The desire in the standards developing
      community, including the IETF, to be programming language agnostic
      and to avoid API standardization may need to be re-visited in
      light of these recent developments.  Extending JavaScript may, for
      example, require new Document Object Models (DOMs) [45] and these
      could serve as a valuable contribution.

   Offering almost unlimited capabilities to JavaScript/HTML running in
   a browser (in the same style as native applications run in an
   operating system environment) will raise security concerns and will
   consequently require countermeasures (such as 'deep inspection' and
   blocking).  This in turn will sparkle new ideas to bypass limitations
   introduced, for example by utilizing new scripting languages with
   different capabilities, etc.  This is an arms race that the IT
   industry is already able to observe already with deep packet
   inspection firewalls and peer-to-peer networks during the last few

   It is unavoidable to get the impression that the hard problems,
   particularly to security concerns regarding the distribution of new
   software in whatever form, have not been tackled.  Instead, the
   browser becomes the new operating system, inherits the same
   weaknesses and is likely to share the same fate.

Tschofenig, et al.      Expires November 10, 2012              [Page 15]

Internet-Draft  Web Applications: Trends and Implications       May 2012

6.  Security Considerations

   This document includes discussions related to security.

Tschofenig, et al.      Expires November 10, 2012              [Page 16]

Internet-Draft  Web Applications: Trends and Implications       May 2012

7.  IANA Considerations

   This document does not require actions by IANA.

Tschofenig, et al.      Expires November 10, 2012              [Page 17]

Internet-Draft  Web Applications: Trends and Implications       May 2012

8.  Acknowledgements

   The authors would like to thank Gonzalo Camarillo, Robert Sparks,
   Alissa Cooper, Blaine Cook, Alexey Melnikov, Peter Saint-Andre,
   Jonathan Rosenberg, Lisa Dusseault, Joshua Bell, John Hurliman,
   Meadhbh Hamrick, Mark Nottingham, Anders Rundgren, Markus Isomaki,
   Spencer Dawkins, Jan Kall, Jan Ignatius and Thomas Roessler.

   An early version of this document was written to provide additional
   background for the IETF#80 IAB technical plenary discussion in
   Prague, March 2011.  A number of persons provided their feedback,
   including Dave Crocker, Pete Resnick, Leslie Daigle, Harald
   Alvestrand, Jonathan Rosenberg, Dave Cridland, Nico Williams, Peter
   Saint-Andre, Graham Klyne, Philip Hallam-Baker, Scott Brim, Henry
   Sinnreich, Eliot Lear, Mark Nottingham, Paul Hoffman, Ted Hardie,
   Cyrus Daboo, Claudio Allocchio, and Sam Hartman.  We thank them for
   the lively discussion.

Tschofenig, et al.      Expires November 10, 2012              [Page 18]

Internet-Draft  Web Applications: Trends and Implications       May 2012

9.  Informative References

   [1]   Myers, J. and M. Rose, "Post Office Protocol - Version 3",
         STD 53, RFC 1939, May 1996.

         4rev1", RFC 3501, March 2003.

   [3]   Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
         Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
         Session Initiation Protocol", RFC 3261, June 2002.

   [4]   Saint-Andre, P., Ed., "Extensible Messaging and Presence
         Protocol (XMPP): Core", RFC 3920, October 2004.

   [5]   "W3C HTML Working Group Charter", Sep 2010.

   [6]   "V8 JavaScript Engine", Sep 2010.

   [7]   "V8 JavaScript Engine - Design Elements", Sep 2010.

   [8]   "WebGL", Sep 2010.

   [9]   "Quake II Google Web Toolkit (GWT) Port", Sep 2010.

   [10]  "The WebSocket API", Sep 2010.

   [11]  "Web Storage", Aug 2010.

   [12]  "Second Life", Sep 2010.

   [13]  "Private communication between Joshua Bell, Hannes Tschofenig
         and Jon Peterson about browser performance limitations",
         Aug 2010.

   [14]  "Elevating JavaScript Performance Through GPU Power", Jan 2010.

   [15]  "Jetpack 0.5 Contest: A Winner", Nov 2009.

   [16]  Rosenberg, J., "UDP and TCP as the New Waist of the Internet
         Hourglass", draft-rosenberg-internet-waist-hourglass-00 (work
         in progress), February 2008.

   [17]  Rosenberg, J., "Interactive Connectivity Establishment (ICE): A
         Protocol for Network Address Translator (NAT) Traversal for
         Offer/Answer Protocols", RFC 5245, April 2010.

   [18]  "SPDY: An experimental protocol for a faster web", Oct 2011.

Tschofenig, et al.      Expires November 10, 2012              [Page 19]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   [19]  Westerlund, M., Burman, B., and C. Perkins, "RTP Multiplexing
         draft-westerlund-avtcore-multiplex-architecture-01 (work in
         progress), March 2012.

   [20]  "Google Talk for Developers: Important Concepts", Sep 2010.

   [21]  "JavaScript Implementation of AES Advanced Encryption Standard
         in Counter Mode", Sep 2010.

   [22]  "crypto-js: JavaScript implementations of standard and secure
         cryptographic algorithms", Sep 2010.

   [23]  "JavaScript Crypto", Sep 2010.

   [24]  "W3C Web Applications (WebApps) Working Group", Sep 2010.

   [25]  "JavaScript Object Notation (JSON)", Sep 2010.

   [26]  "The GeoJSON Format Specification", Jun 2008.

   [27]  Peterson, J., "A Presence-based GEOPRIV Location Object
         Format", RFC 4119, December 2005.

   [28]  "XEP-0080: User Location", Sep 2009.

   [29]  Peterson, J., "A Privacy Mechanism for the Session Initiation
         Protocol (SIP)", RFC 3323, November 2002.

   [30]  Munakata, M., Schubert, S., and T. Ohba, "Guidelines for Using
         the Privacy Mechanism for SIP", RFC 5379, February 2010.

   [31]  Munakata, M., Schubert, S., and T. Ohba, "User-Agent-Driven
         Privacy Mechanism for SIP", RFC 5767, April 2010.

   [32]  Crockford, D., "(JavaScript) Minification v Obfuscation",
         Mar 2006.

   [33]  "nodeJS", Sep 2010.

   [34]  "CommonJS", Sep 2010.

   [35]  "IETF BiDirectional or Server-Initiated HTTP (hybi) Working
         Group Charter", Mar 2011.

   [36]  "Let's make the web faster", Sep 2010.

   [37]  "IETF Web Security (websec) Working Group Charter", Mar 2011.

Tschofenig, et al.      Expires November 10, 2012              [Page 20]

Internet-Draft  Web Applications: Trends and Implications       May 2012

   [38]  "Data Portability Project: Share and Remix Data using Open
         Standards", Sep 2010.

   [39]  "IETF Open Authentication Protocol (oauth) Working Group
         Charter", Sep 2010.

   [40]  "jQuery: The Write Less, Do More, JavaScript Library",
         Sep 2010.

   [41]  "Prototype JavaScript framework: Easy Ajax and DOM anipultion
         for dynamic web applications", Sep 2010.

   [42]  "MooTools - a compact javascript framework", Sep 2010.

   [43]  "Yahoo! User Interface Library 3", Sep 2010.

   [44]  "Narwhal - A general purpose JavaScript platform", Sep 2010.

   [45]  "Document Object Model", Sep 2010.

   [46]  "W3C Workshop on Privacy for Advanced Web APIs", Jul 2010.

   [47]  "W3C Geolocation Working Group", Sep 2010.

   [48]  "Ajax (programming)", Sep 2010.

   [49]  "Device APIs and Policy Working Group", Sep 2010.

   [50]  Doty, N., Mulligan, D., and E. Wilde, "Privacy Issues of the
         W3C Geolocation API, UC Berkeley School of Information Report
         2010-038", Feb 2010.

   [51]  "Adobe Flash Player", Sep 2010.

   [52]  "Microsoft Silverlight", Sep 2010.

Tschofenig, et al.      Expires November 10, 2012              [Page 21]

Internet-Draft  Web Applications: Trends and Implications       May 2012

Authors' Addresses

   Hannes Tschofenig
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  02600

   Phone: +358 (50) 4871445

   Bernard Aboba
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052


   Jon Peterson
   NeuStar, Inc.
   1800 Sutter St Suite 570
   Concord, CA  94520


   Danny McPherson


Tschofenig, et al.      Expires November 10, 2012              [Page 22]