> I started to tag as #ItsAGraph, #NotATree

Oh, epic! While I do agree that most things that are modeled as yes are conceptually actually graphs, maybe my standards are lower/I just use worse software - I'd be very happy to get more trees. My typical rant topic is "just give me a damn tree". The worst offenders regarding this I can think of are note apps with their weird "notebook", "chapter","page" concepts rather than just letting me choose the depth of nesting I need.

Sort of feels like an extension of the 0/1/many concept.

I feel the pain. So much software doesn't even expose a proper tree, much less a DAG. But that seems to be improving somewhat - I see trees in software more often. I just worry I'll retire before the ecosystem makes the cognitive jump to start implementing/exposing DAGs.

> I can think of are note apps with their weird "notebook", "chapter","page" concepts rather than just letting me choose the depth of nesting I need.

Exactly! And then you end up using "outliner" software for this, and then people are surprised that you need rich text capabilities in it. In reality, what's needed is to combine both, to get a note-taking app with arbitrary nesting levels.

I made Recall[0] which is all about this. Managing tasks using a tree structure (like folder/files, no level limit). And dependency representation with DAG graphs. Give it a try, you might like it.

Unfortunately the project is currently paused since i can't figure out how to make it work financially (you can still use it though). The space is really crowded and most people don't really think about dependencies, so it's quite a hard sell.

I might open-source the project and continue with it in the near future but I'll need some validation that the tool is useful before I commit to that. So if you do like it, I'd love to have a chat :)

[0] https://recalllab.com

On mobile now. I skimmed the landing page and this looks interesting, I'll check it out after the weekend. Thanks!

I wonder if there's a site where someone trying to work out whether to continue a business could post how much money they would accept to instead open source it, and then that amount could be crowdfunded by its users, or just people (this would be me in this case, I guess) who aren't current users but think it looks like it would be a valuable contribution to the world.

Have you tried Trilium (https://github.com/zadam/trilium)?

It's a generic note storage (with a DAG based model) that's very extensible and comes with a demo task manager implementation: https://github.com/zadam/trilium/wiki/Task-manager

Thanks for the link, I haven't seen it.

Skimming through their Wiki, it looks like a tree-oriented outliner with a link graph - i.e. a similar model to what Roam, Obsidian, Logseq or org-mode (especially when paired with org-roam) offers.

This is as close as I've seen graphs at the UI level to hit mainstream, and the extreme hype generated around this class of tools (and Zettelkasten) when Roam showed up was interesting to watch - people reacted to this as if it was pure magic.

> This. To me, it seems like a weird market blind spot. Most of the tools in this space can't even do a proper tree - typically they limit you to 2-4 levels, like "project", "task", "subtask" and "checklist". The few that don't, stick to the tree model, even though work naturally structures itself into a DAG.

I did wonder that myself. But having tried implementing, I'd wager that deep many-to-many parent-child relationships are not directly visible more often is because no one has figured out good paradigms [1] to surface the functionality in a way that users would want to use most of the time (witness MS Project) versus the alternative tags, saved search, etc approaches.

[1] It's a fairly chunky challenge. Consider for example, what happens, and how is it presented to the user during the simple operation of removing an item. What happens when it has multiple parents? What about if it also has child dependencies? What about if some of those children have different ancestors? And it must be undoable and also needs to be usable on the limited screen estate of a mobile phone? ...

> I'd wager that deep many-to-many parent-child relationships are not directly visible more often is because no one has figured out good paradigms [1] to surface the functionality in a way that users would want to use most of the time

I suspect that might be a big part of the reason. I believe [0] that one big change that happens when you "upgrade" from a tree to a DAG is that you lose the ability to visualize your model in a compact and direct plaintext form

Sequences you can print an item per line, or separate by commas. Trees you can visualize with indentation, possibly decorating with some form of arrows. But DAGs seem to require you either use indirect references[1] (or duplication, which is just a more verbose and limited form of references), or give up and start drawing arrows and boxes. There's a qualitative jump in difficulty here - you (or rather, the software) needs to start thinking about layout, which is pretty much a non-issue with trees.

The biggest problems are with the evolution of the data structure. Trees and sequences don't "jump around" when you add or remove single nodes - edits cause, at worst small local rearrangement, and the rest of the tree is shifted to make/take space. DAGs are the first stage in this "from sequences to graphs" progression at which any single edit could force you to re-layout the entire visualization to keep it readable.

I have one nit though:

> And it (...) also needs to be usable on the limited screen estate of a mobile phone?

This is true now, but it wasn't true just a few years ago. Where are all the products from the last decade, that didn't have the "design for smartphones" constraint?

--

[0] - I strongly suspect this to be a mathematical fact, but I haven't encountered a proof of it.

[1] - If you want to keep parents next to their children, you're almost always forced to start doing things like:

  #1=Parent1 ----v
  Parent2  ---> Child1

  Parent3 ---> Child2
           #1# --^

... which kills readability, as now the reader has to keep a cache of those labels and dereference pointers in their head. If, instead of references (like #1#) you just duplicate the node (e.g. write "Parent1" again), the reader still has to keep a mental map of which nodes are represented multiple times in the text, and which are just similarly named.