What is Hypermedia anyway?

Hypermedia is a general term for a system of media organisation that provisions for:
    Referencing: To point one part of the media to another.
    Back-Referencing: To see what parts of the media is referencing one part
    Transclusion: An excerpt that is also a reference.
There is also a week version of hypermedia which contains only one way references. The WWW provides such a hypermedia system.
Hypermedia is also the name of this system. Unless I state specifically by using monospace, I reserve the word for the general concept. Hypermedia As explained by its developers:
There are many people who have layed there mark on the development of hypermedia. One of the seminal figures is Ted Nelson.
I have some thoughts about the essential elements, and full exstent of what hypermedia can be

Non-linearity

In its stricktest meaning, hypermedia is media authors to allow for non-linear traversal.
In its more general scene, its media as a system, which literately changes its self, at a textual level, to the users.
I have used the plural of media, because one of the most interesting possibilities that hypermedia introduces is its social component.
All media is fundamentally a medium for communication. However, hypermedia can brake down the directional between the author and the reader. Instead both become users, and users may interact with the system that is generative of that system, at a textual level.
As Engelhart saw it, hypermedia is a technetium for collective intelligence.
Hypermedia also the relationship of different texts with each-other, its interconnecting cross-references makes adjacent hypermedia fuse, and hypermedia surround and consume non-hypermedia.
Hypermedia brakes down linearity in 3 ways:
    The trajectory of the reader. The defining feature of hypermedia is for a branching and interconnecting reading experience. Non-linearity and engagement is the essence of hypermedia.
    The relationship between the author and the readers. Readers can add to the materiel and make there own connections. Indeed they can use the media as a space that facilitates and shapes engagement with not only the intention of the author but with each-other. In so doing, the generate the text of the medium its self. In the limit, each reader is as much an author. Both are users, and users are both. Thus hypermedia becomes social-media
    The relationship between adjacent medium. Since media can interconnect with one-another, if the do so at sufficient density, they form a larger hypermedia. Thus hypermedia becomes trans-media.
In inviting, and allowing the participation of the reader at a textual level, bringing them in as authors, hypermedia transcends Thing and becomes Place.
Hypermedia may seem dominant today, due to the web. It may seem like we know what it is and what its limits are. But I contend that hypermedia is a design-space which we have barely charted. Its a great to sea, and we have hitherto sticking only to a few consensual barbers.

Hypermedia is multimedia

A full realisation of a hypermedia system should be able to decompose and link video and audio on the same footing as text.
The deeper the hypermedia system can penetrate into the internal structure of the media its devour the more powerful and the move valuable it can be.
Thus the design of such a system should be open ended and aggressive in its devouring.

Hyper Video

Currently in minted, a video can be linked, or it can be embedded, or attached as a file. But if we were really pushing, how deep into the internal structure of the vidoe could we push?
For the sake of illustration and differentiation, let me brake down the possibilities into levels 5:
At level 0 we have simply including the artefact in its entirety as a blob. Not acknowledging its internal structure.
At level 1 we can acknowledge its first major structure, its extension in time. That is we can reference things by time stamp.
At level 2 we can acknowledge its channels, audio and video, perhaps the transcript.
At level 3 we can acknowledge the spacial variation, referencing specific frames of the video and points on those frames.
At level 4 we can acknowledge the composition, that is the source clips. Now we are really getting somewhere, by braking down a video into its components, the components that created it in the first place, the hypermedia becomes a means to remix, and recombine videos, as it is to remix and recombine text. And with a content addressed sub-straight, provenience and referencing is integrated to.'
Ted Nelson explains this in one of his Xanadu explainer videos. He also mentions a new defunct project called popcorn maker. The associated TED talk is still relevant. However they have an outbound orientation. That the video has links out, and can thus pull information in. However the more useful aspect of making video hypermedia, is I believe the inbound direction. Of being able to pull apart, dissect and remix existing videos. That is its more interesting when its affordances to the commented.
Here, someone has written HTML-5 controls that extracts time stamps from video and audio in a web friendly way.

Hyper Code

This section is deprecated. I have a much better explanation here.
Is it possible to inpeasescorporate computation into hypertext, as hypertext, and to do so in a safe way. If we could have code that stitches patches together in some deterministic way, This might aid in incorporating the inner structure of other media. For example in Level 4 video, representing a video by reference to constituent parts that are fitted together in a definite way is an interesting possibility, but it would requiter computation-on-demand.
Running random code pulled from the internet, even if its from someone you have "trusted" is not a reassuring thought. However I believe web-assembly might provide a viable and secure medium to incorporate computation as hypermedia.
WebAssembly can be run without being given access to random numbers, so it may be possible to have reliably deterministic code. deterministic code that connects two content addressed blobs.

Hypermedia means bigdata

A hypermedia system is more useful the more it can ingest, and one of the powers of a design is the constrains on its digestion process. If the system cant scail to arbitrary data. If say it cant read a document larger then the memory of the computer, then this will pose a limit to its growth. Thus lazy loading, and fin-grande discretionary data retrieval should be fundamental.