2 December 2005
The RSL Hypermedia Metamodel and Its
Application in Cross-Media Solutions
Prof. Beat Signer
beatsigner.com
Web & Information Systems Engineering Lab
Department of Computer Science
Vrije Universiteit Brussel
01001000100
0101001100010010100010010
0100100010010001000100001001000
100010001100001001000110010101010110
1100010010100010010010010100010101011001
101001100001100 101010100
0010100 100 110101010101
00100 01010101000
1001 1111111111
111 0000000010
0 11111111
0101001011
010101010
111010101
001010010110
Cross-Media Information Spaces
Fragmentation of information
across different applications,
devices and digital & physical
information environments
Information
Systems &
Management
Information
Visualisation
& Navigation
Information
Visualisation
nd Navigation
Human-Machine &
Human-Information
Interaction
CISA
RSL
MindXpres
OC2
associative file system
data-driven storytelling
XIMA
cross-device interaction
iServer/iPaper
ViDaX
data physicalisation
OpenHPS
non-linear storytelling
PaperProof
iGesture
PaperSketch
TangHo
Context Modelling Toolkit
Midas
SpeeG2
PaperPoint
Print-n-Link
digital libraries
Mudra mixed reality
ArtVis
open cross-media linking
PimVis
DocTr
EdFest
source code visualisation
INFEX
technology-enhanced learning
Cross-Media Technologies WEB & INFORMATION
SYSTEMS ENGINEERING
Data-centric approach for
cross-media information
solutions based on a
hypermedia metamodel
Cross-Media Linking
Flexible Document Representation
Cross-Media User Interfaces
RSL Hypermedia Metamodel & Link Server
B. Signer and M.C. Norrie, As We May Link: A General Meta-
model for Hypermedia Systems, Proceedings of ER 2007x
RSL Hypermedia Metamodel
B. Signer and M.C. Norrie, As We May Link: A General Meta-
model for Hypermedia Systems, Proceedings of ER 2007x
Interactive Paper (EdFest)
B. Signer, M. Grossniklaus and M.C. Norrie, Interactive Paper as a Mobile
Client for a Multi-Channel Web Information System WWWJ 10(4), 2007 x
PimVis Personal Information Management
S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding
Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
PimVis Setup
S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding
Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
PimVis Document View
S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding
Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
PimVis Focus View
S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding
Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
Object-Concept-Context (OC2) Model
object layer
structural link
concept layer
context layer
navigational link
associative link
weighted link
Object 1 Object n
Object 2
Context 1 Context n
Concept 1
Concept 2 Concept n
extent link
OC2 conceptual model
RSL-based metamodel
S. Trullemans and B. Signer, Towards a Conceptual Framework and Metamodel for Context-
aware Personal Cross-Media Information Management Systems, Proceedings of ER 2014
Cross-Media Linking
Flexible Document Representation
Cross-Media User Interfaces
What is Wrong with Digital Documents?
Most people don't understand the logic of the concept:
"What You See Is What You Get" is based on printing
the document out ("get" means "get WHEN YOU
PRINT IT OUT"). And that means a metaphysical shift:
a document can only consist of what can be printed!
[...] No overlays [...] – PAPER UNDER GLASS.
Ted Nelson, Geeks Bearing Gifts: How the Computer World Got This Way, Mindful Press 2009
Existing document formats often based on
the simulation of paper affordances on
desktop computers
B. Signer, What is Wrong with Digital Documents? A Conceptual Model for Struc-
tural Cross-Media Content Composition and Reuse, Proceedings of ER 2010
What is Wrong with Slideware?
▪ Simulation of physical slides
▪ limited space due to slide concept
▪ linear navigation
▪ monolithic documents
▪ difficult to reuse content and embed rich media types
MindXpres Presentation Platform
▪ Flexible representation
of presentations
▪ use of structural RSL links
▪ separation of content and
structure
▪ Extensible platform
▪ content-based approach
▪ cross-media content reuse
via transclusion
▪ non-linear navigation and
zoomable user interface
▪ associative linking
▪ rich media types
R. Roels and B. Signer, MindXpres: An Extensible Content-driven
Cross-Media Presentation Platform, Proceedings of WISE 2014
MindXpres Document Representation
R. Roels and B. Signer, A Conceptual Framework and Content Model for
Next Generation Presentation Solutions, PACMHCI 3(Issue EICS), 2019
MindXpres (Video)
Different context-dependent
adaptive overlay structures on top
of (parts of) content
Clear separation between content
and structure enables cross-media
content reuse (transclusion)
Cross-Media Linking
Flexible Document Representation
Cross-Media User Interfaces
PimVis Personal Information Management
S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding
Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
eSPACE Framework for Hybrid UIs
A. Sanctorum and B. Signer, A Unifying Reference Framework and Model
for Adaptive Distributed Hybrid User Interfaces, Proceedings of RCIS 2019
x
XR-based Interaction
▪ Controlling individual IoT
devices
▪ Define relationships and
rules between IoT devices
▪ Linking any physical
artefact to other physical
artefacts or digital
information and services
▪ use of natural (pointing)
gestures and interactions
▪ “drag and drop” between
IoT devices
Elena Zambon
Tangible Holograms (TangHo)
The Lost Cosmonaut
▪ Writing as a collaborative
act of memory and story-
telling
▪ Reading, writing and
narrative as an act of
making sense
▪ Handwriting as a tool
for human-computer
interaction
In collaboration with Axel Vogelsang,
Artists in Labs Programme
A. Vogelsang and B. Signer, The Lost Cosmonaut: An Interactive Narrative En-
vironment on Basis of Digitally Enhanced Paper, Proceedings of ICVS 2005
Open Cross-Media Linking
local visual plug-ins
external visual plug-ins
communicate
Cross-Media Link Browser & Editor
Unified Cross-Media Information Spaces
Common underlying
representation of data, cross-
media links and structures via
RSL-based hypermedia engine
supporting legacy applications
RSL-based Hypermedia Engine
RSL-based Hypermedia Engine
Legacy Applications
File System Driver
Hypermedia-enabled Applications
HT2021.docx
HT2021.docx
…
B. Signer, R. Roels, R. van Barlingen and B. Willems, Back to the Future: Bringing Original Hyper-
media and Cross-Media Concepts to Modern Desktop Environments, Proceedings of Hypertext 2021
RSL-based Hypermedia Engine …
signer
My Pictures
Vancouver ER 2010
Granville
Island
Vancouver
Harbour
Public
Market
Keynote
J. Thorp
Olga and
Lamia
Dinner
ER 2010
multiple classification
structural link
navigational link
My Videos
Vancouver
Aquarium
ER 2010
Keynote
cross-media association
My Presentations
ER 2010 WISE 2009
cross-media
transclusion
single slide
transclusion
(via OOXML
RSL selector)
Next Generation File Manager
B. Signer, R. Roels, R. van Barlingen and B. Willems, Back to the Future: Bringing Original Hyper-
media and Cross-Media Concepts to Modern Desktop Environments, Proceedings of Hypertext 2021
System-wide hypermedia engine
at operating system level, enabling
cross-media information manage-
ment across application boundaries
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 34
June 6, 2023
References
▪ B. Signer, Fundamental Concepts for
Interactive Paper and Cross-Media Information
Spaces, Second Edition, ISBN 978-3-8370-2713-6,
August 2017
▪ B. Signer and M.C. Norrie, As We May Link: A General
Metamodel for Hypermedia Systems, Proceedings of
ER 2007, 26th International Conference on Conceptual
Modeling, Auckland, New Zealand, November 2007
▪ https://beatsigner.com/publications/signer_ER2007.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 35
June 6, 2023
References ...
▪ B. Signer, Towards Cross-Media Information
Spaces and Architectures, Proceedings of RCIS 2019,
13th International Conference on Research Challenges
in Information Science, Brussels, Belgium, May 2019
▪ https://beatsigner.com/publications/signer_RCIS2019.pdf
▪ B. Signer, M. Grossniklaus and M.C. Norrie,
Interactive Paper as a Mobile Client for a Multi-Channel
Web Information System, World Wide Web Journal
(WWW), Vol. 10, No. 4, Springer, December 2007
▪ https://beatsigner.com/publications/signer_WWWJ2007.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 36
June 6, 2023
References ...
▪ S. Trullemans, A. Sanctorum and B. Signer,
PimVis: Exploring and Re-finding Documents in Cross-
Media Information Spaces, Proceedings of AVI 2016,
International Working Conference on Advanced Visual
Interfaces, Bari, Italy, June 2016
▪ https://beatsigner.com/publications/trullemans_AVI2016.pdf
▪ S. Trullemans and B. Signer, Towards a Conceptual
Framework and Metamodel for Context-aware Personal
Cross-Media Information Management Systems, Pro-
ceedings of ER 2014, 33rd International Conference on
Conceptual Modelling, Atlanta, USA, October, 2014
▪ https://beatsigner.com/publications/trullemans_ER2014.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 37
June 6, 2023
References ...
▪ B. Signer, What is Wrong with Digital Documents?
A Conceptual Model for Structural Cross-Media Content
Composition and Reuse, Proceedings of ER 2010,
29th International Conference on Conceptual Modeling,
Vancouver, Canada, November 2010
▪ https://beatsigner.com/publications/signer_ER2010.pdf
▪ R. Roels and B. Signer, MindXpres: An
Extensible Content-driven Cross-Media Presentation
Platform, Proceedings of WISE 2014, 15th International
Conference on Web Information System Engineering,
Thessaloniki, Greece, October 2014
▪ https://beatsigner.com/publications/roels_WISE2014.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 38
June 6, 2023
References ...
▪ R. Roels and B. Signer, A Conceptual Frame-
work and Content Model for Next Generation
Presentation Solutions, Proceedings of the ACM on
Human-Computer Interaction (PACMHCI), 2019
▪ https://beatsigner.com/publications/roels_PACMHCI2019.pdf
▪ A. Sanctorum and B. Signer, A Unifying Reference
Framework and Model for Adaptive Distributed Hybrid
User Interfaces, Proceedings of RCIS 2019,
13th International Conference on Research Challenges
in Information Science, Brussels, Belgium, May 2019
▪ https://beatsigner.com/publications/sanctorum_RCIS2019.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 39
June 6, 2023
References ...
▪ A. Vogelsang and B. Signer, The Lost Cosmonaut:
An Interactive Narrative Environment on Basis of
Digitally Enhanced Paper, Proceedings of the Inter-
national Conference on Virtual Storytelling 2005,
Strasbourg, France, December 2005
▪ https://beatsigner.com/publications/vogelsang_ICVS2005.pdf
▪ A.A.O. Tayeh, Payam Ebrahimi and Beat Signer, Cross-
Media Document Linking and Navigation, Proceedings
of DocEng 2018, 18th ACM Symposium on Document
Engineering, Halifax, Canada, August 2018
▪ https://beatsigner.com/publications/tayeh_DocEng2018.pdf
Beat Signer - Department of Computer Science - bsigner@vub.ac.be 40
June 6, 2023
References ...
▪ B. Signer, R. Roels, R. van Barlingen and
B. Willems, Back to the Future: Bringing Original
Hypermedia and Cross-Media Concepts to Modern
Desktop Environments, Proceedings of Hypertext 2021,
Virtual Event, August 2021
▪ https://beatsigner.com/publications/signer_Hypertext2021.pdf

The RSL Hypermedia Metamodel and Its Application in Cross-Media Solutions

  • 1.
    2 December 2005 TheRSL Hypermedia Metamodel and Its Application in Cross-Media Solutions Prof. Beat Signer beatsigner.com Web & Information Systems Engineering Lab Department of Computer Science Vrije Universiteit Brussel
  • 2.
    01001000100 0101001100010010100010010 0100100010010001000100001001000 100010001100001001000110010101010110 1100010010100010010010010100010101011001 101001100001100 101010100 0010100 100110101010101 00100 01010101000 1001 1111111111 111 0000000010 0 11111111 0101001011 010101010 111010101 001010010110 Cross-Media Information Spaces
  • 3.
    Fragmentation of information acrossdifferent applications, devices and digital & physical information environments
  • 4.
    Information Systems & Management Information Visualisation & Navigation Information Visualisation ndNavigation Human-Machine & Human-Information Interaction CISA RSL MindXpres OC2 associative file system data-driven storytelling XIMA cross-device interaction iServer/iPaper ViDaX data physicalisation OpenHPS non-linear storytelling PaperProof iGesture PaperSketch TangHo Context Modelling Toolkit Midas SpeeG2 PaperPoint Print-n-Link digital libraries Mudra mixed reality ArtVis open cross-media linking PimVis DocTr EdFest source code visualisation INFEX technology-enhanced learning Cross-Media Technologies WEB & INFORMATION SYSTEMS ENGINEERING
  • 5.
    Data-centric approach for cross-mediainformation solutions based on a hypermedia metamodel
  • 6.
    Cross-Media Linking Flexible DocumentRepresentation Cross-Media User Interfaces
  • 7.
    RSL Hypermedia Metamodel& Link Server B. Signer and M.C. Norrie, As We May Link: A General Meta- model for Hypermedia Systems, Proceedings of ER 2007x
  • 8.
    RSL Hypermedia Metamodel B.Signer and M.C. Norrie, As We May Link: A General Meta- model for Hypermedia Systems, Proceedings of ER 2007x
  • 9.
    Interactive Paper (EdFest) B.Signer, M. Grossniklaus and M.C. Norrie, Interactive Paper as a Mobile Client for a Multi-Channel Web Information System WWWJ 10(4), 2007 x
  • 10.
    PimVis Personal InformationManagement S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
  • 11.
    PimVis Setup S. Trullemans,A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
  • 12.
    PimVis Document View S.Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
  • 13.
    PimVis Focus View S.Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
  • 14.
    Object-Concept-Context (OC2) Model objectlayer structural link concept layer context layer navigational link associative link weighted link Object 1 Object n Object 2 Context 1 Context n Concept 1 Concept 2 Concept n extent link OC2 conceptual model RSL-based metamodel S. Trullemans and B. Signer, Towards a Conceptual Framework and Metamodel for Context- aware Personal Cross-Media Information Management Systems, Proceedings of ER 2014
  • 15.
    Cross-Media Linking Flexible DocumentRepresentation Cross-Media User Interfaces
  • 16.
    What is Wrongwith Digital Documents? Most people don't understand the logic of the concept: "What You See Is What You Get" is based on printing the document out ("get" means "get WHEN YOU PRINT IT OUT"). And that means a metaphysical shift: a document can only consist of what can be printed! [...] No overlays [...] – PAPER UNDER GLASS. Ted Nelson, Geeks Bearing Gifts: How the Computer World Got This Way, Mindful Press 2009 Existing document formats often based on the simulation of paper affordances on desktop computers B. Signer, What is Wrong with Digital Documents? A Conceptual Model for Struc- tural Cross-Media Content Composition and Reuse, Proceedings of ER 2010
  • 17.
    What is Wrongwith Slideware? ▪ Simulation of physical slides ▪ limited space due to slide concept ▪ linear navigation ▪ monolithic documents ▪ difficult to reuse content and embed rich media types
  • 18.
    MindXpres Presentation Platform ▪Flexible representation of presentations ▪ use of structural RSL links ▪ separation of content and structure ▪ Extensible platform ▪ content-based approach ▪ cross-media content reuse via transclusion ▪ non-linear navigation and zoomable user interface ▪ associative linking ▪ rich media types R. Roels and B. Signer, MindXpres: An Extensible Content-driven Cross-Media Presentation Platform, Proceedings of WISE 2014
  • 19.
    MindXpres Document Representation R.Roels and B. Signer, A Conceptual Framework and Content Model for Next Generation Presentation Solutions, PACMHCI 3(Issue EICS), 2019
  • 20.
  • 21.
    Different context-dependent adaptive overlaystructures on top of (parts of) content Clear separation between content and structure enables cross-media content reuse (transclusion)
  • 22.
    Cross-Media Linking Flexible DocumentRepresentation Cross-Media User Interfaces
  • 23.
    PimVis Personal InformationManagement S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross-Media Information Spaces, Proceedings of AVI 2016
  • 24.
    eSPACE Framework forHybrid UIs A. Sanctorum and B. Signer, A Unifying Reference Framework and Model for Adaptive Distributed Hybrid User Interfaces, Proceedings of RCIS 2019 x
  • 25.
    XR-based Interaction ▪ Controllingindividual IoT devices ▪ Define relationships and rules between IoT devices ▪ Linking any physical artefact to other physical artefacts or digital information and services ▪ use of natural (pointing) gestures and interactions ▪ “drag and drop” between IoT devices Elena Zambon Tangible Holograms (TangHo)
  • 26.
    The Lost Cosmonaut ▪Writing as a collaborative act of memory and story- telling ▪ Reading, writing and narrative as an act of making sense ▪ Handwriting as a tool for human-computer interaction In collaboration with Axel Vogelsang, Artists in Labs Programme A. Vogelsang and B. Signer, The Lost Cosmonaut: An Interactive Narrative En- vironment on Basis of Digitally Enhanced Paper, Proceedings of ICVS 2005
  • 27.
    Open Cross-Media Linking localvisual plug-ins external visual plug-ins communicate Cross-Media Link Browser & Editor
  • 28.
  • 29.
    Common underlying representation ofdata, cross- media links and structures via RSL-based hypermedia engine supporting legacy applications
  • 30.
    RSL-based Hypermedia Engine RSL-basedHypermedia Engine Legacy Applications File System Driver Hypermedia-enabled Applications HT2021.docx HT2021.docx … B. Signer, R. Roels, R. van Barlingen and B. Willems, Back to the Future: Bringing Original Hyper- media and Cross-Media Concepts to Modern Desktop Environments, Proceedings of Hypertext 2021
  • 31.
    RSL-based Hypermedia Engine… signer My Pictures Vancouver ER 2010 Granville Island Vancouver Harbour Public Market Keynote J. Thorp Olga and Lamia Dinner ER 2010 multiple classification structural link navigational link My Videos Vancouver Aquarium ER 2010 Keynote cross-media association My Presentations ER 2010 WISE 2009 cross-media transclusion single slide transclusion (via OOXML RSL selector)
  • 32.
    Next Generation FileManager B. Signer, R. Roels, R. van Barlingen and B. Willems, Back to the Future: Bringing Original Hyper- media and Cross-Media Concepts to Modern Desktop Environments, Proceedings of Hypertext 2021
  • 33.
    System-wide hypermedia engine atoperating system level, enabling cross-media information manage- ment across application boundaries
  • 34.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 34 June 6, 2023 References ▪ B. Signer, Fundamental Concepts for Interactive Paper and Cross-Media Information Spaces, Second Edition, ISBN 978-3-8370-2713-6, August 2017 ▪ B. Signer and M.C. Norrie, As We May Link: A General Metamodel for Hypermedia Systems, Proceedings of ER 2007, 26th International Conference on Conceptual Modeling, Auckland, New Zealand, November 2007 ▪ https://beatsigner.com/publications/signer_ER2007.pdf
  • 35.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 35 June 6, 2023 References ... ▪ B. Signer, Towards Cross-Media Information Spaces and Architectures, Proceedings of RCIS 2019, 13th International Conference on Research Challenges in Information Science, Brussels, Belgium, May 2019 ▪ https://beatsigner.com/publications/signer_RCIS2019.pdf ▪ B. Signer, M. Grossniklaus and M.C. Norrie, Interactive Paper as a Mobile Client for a Multi-Channel Web Information System, World Wide Web Journal (WWW), Vol. 10, No. 4, Springer, December 2007 ▪ https://beatsigner.com/publications/signer_WWWJ2007.pdf
  • 36.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 36 June 6, 2023 References ... ▪ S. Trullemans, A. Sanctorum and B. Signer, PimVis: Exploring and Re-finding Documents in Cross- Media Information Spaces, Proceedings of AVI 2016, International Working Conference on Advanced Visual Interfaces, Bari, Italy, June 2016 ▪ https://beatsigner.com/publications/trullemans_AVI2016.pdf ▪ S. Trullemans and B. Signer, Towards a Conceptual Framework and Metamodel for Context-aware Personal Cross-Media Information Management Systems, Pro- ceedings of ER 2014, 33rd International Conference on Conceptual Modelling, Atlanta, USA, October, 2014 ▪ https://beatsigner.com/publications/trullemans_ER2014.pdf
  • 37.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 37 June 6, 2023 References ... ▪ B. Signer, What is Wrong with Digital Documents? A Conceptual Model for Structural Cross-Media Content Composition and Reuse, Proceedings of ER 2010, 29th International Conference on Conceptual Modeling, Vancouver, Canada, November 2010 ▪ https://beatsigner.com/publications/signer_ER2010.pdf ▪ R. Roels and B. Signer, MindXpres: An Extensible Content-driven Cross-Media Presentation Platform, Proceedings of WISE 2014, 15th International Conference on Web Information System Engineering, Thessaloniki, Greece, October 2014 ▪ https://beatsigner.com/publications/roels_WISE2014.pdf
  • 38.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 38 June 6, 2023 References ... ▪ R. Roels and B. Signer, A Conceptual Frame- work and Content Model for Next Generation Presentation Solutions, Proceedings of the ACM on Human-Computer Interaction (PACMHCI), 2019 ▪ https://beatsigner.com/publications/roels_PACMHCI2019.pdf ▪ A. Sanctorum and B. Signer, A Unifying Reference Framework and Model for Adaptive Distributed Hybrid User Interfaces, Proceedings of RCIS 2019, 13th International Conference on Research Challenges in Information Science, Brussels, Belgium, May 2019 ▪ https://beatsigner.com/publications/sanctorum_RCIS2019.pdf
  • 39.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 39 June 6, 2023 References ... ▪ A. Vogelsang and B. Signer, The Lost Cosmonaut: An Interactive Narrative Environment on Basis of Digitally Enhanced Paper, Proceedings of the Inter- national Conference on Virtual Storytelling 2005, Strasbourg, France, December 2005 ▪ https://beatsigner.com/publications/vogelsang_ICVS2005.pdf ▪ A.A.O. Tayeh, Payam Ebrahimi and Beat Signer, Cross- Media Document Linking and Navigation, Proceedings of DocEng 2018, 18th ACM Symposium on Document Engineering, Halifax, Canada, August 2018 ▪ https://beatsigner.com/publications/tayeh_DocEng2018.pdf
  • 40.
    Beat Signer -Department of Computer Science - bsigner@vub.ac.be 40 June 6, 2023 References ... ▪ B. Signer, R. Roels, R. van Barlingen and B. Willems, Back to the Future: Bringing Original Hypermedia and Cross-Media Concepts to Modern Desktop Environments, Proceedings of Hypertext 2021, Virtual Event, August 2021 ▪ https://beatsigner.com/publications/signer_Hypertext2021.pdf