graphviz

There are more than enough published algorithms in the last 10-20 years, but the open source model doesn't attract contributors to implement them. It takes relatively difficult, intricate work in a niche area. It's not the Linux kernel, or an AI startup.

It's very good that someone mentioned yed (from yWorks) here. Tom Sawyer Software is also a terrific example of what's possible. Software like that takes a large sustained effort.

"Fix all bugs"?

Is it easy to write a renderer in another program? Do people still say lazyweb?

Gratifying that it's still useful.

A lot of improvements are possible, based on 20 years of progress in interactive systems, and just overall computing performance.

Absolutely.

Various tools use tool-specific graph attributes. For example, "rank" and "minlen" mean something to the hierarchical or layered graph layout tool (dot) but not to other layout tools. "size" and "label" are the same in all the layout tools. They all use the same underlying graph representation library with a parser generated by yacc or bison.

The documentation includes a big table of attributes that graphviz tools recognize.

With the availability of LLMs, there is better automated support now to find features that are needed. Just imagining here, but "make the layout fill the available space" or "make all the nodes look like points with associated text labels" (not sure if that even works but it should).

Don't most companies seek a supported product, like yWorks or Tom Sawyer Software in the case of graph layout?

Isn't the EPL "weak copyleft", so LGPL-ish? Would companies raise similar issues about glibc and GNU libstdc++? Just curious.

One of the nice things about this work is that by assuming the environment is a web client, it supports some basic interactive exploration, and offloads a lot of bothersome rendering problems.

Also, by focusing on control flow graphs, the proposed method does a better job with domain-specific layout. Apparently CFG visualization and exploration is a current topic; e.g. CFGExplorer. Probably Graphviz some users would benefit if it incorporated CFG-friendly level assignment as an option.

There's already machinery in Graphviz to support polylines instead of splines, and to control edge ordering, but it is not well tested or documented. It seems tempting to incorporate an edge routing algorithm of Brandes and Kopf, based on long vertical runs with at most 2 bends per edge. This seems close to a master's degree worth of work to understand and implement.

Graphviz started almost 40 years ago, is only supported by a few (one or two?) 2nd-generation volunteers with no 3rd generation on the scene yet. Over the years we've had plenty of our own disdainful "What is all this junk" moments, about our own code and other people's (c.f. various xkcd comics), but sometimes a better perspective is asking "What is being optimized that led to some team choosing or ending up at this point in the design space". Generally, the market is addicted to features.

It is a little dismaying to see the relatively slow progress in the broad field of declarative 2d diagramming. Given the way the pendulum has swung so hard back toward language based methods and away from using interaction to do everything, you'd think there would be a bigger payoff now for doing the work. Unfortuantely tool-making has always been a tough market. The customers are generally smart, demanding, and work in cost centers so don't have generous budgets.

Interesting, glad to know it's been useful for some specific contributions. (Not questioning that interesting-looking, appealing displays as overviews for general awareness are also worthwhile.)

What do people learn from visualizations like this?

What is the most important problem anyone has solved this way?

Speaking as somewhat of a co-defendant.

And by "system" we mainly meant "transactional website."

We learned the hard way, for some of us it's all too easy to make careless design errors that become baked-in and can't be fixed in a backward-compatible way (either at the DSL or API level). An example in Graphviz is its handling of backslash in string literals: to escape special characters (like quotes \"), to map special characters (like several flavors of newline with optional justification \n \l \r) and to indicate variables (like node names in labels \N) along with magic code that knows that if the -default- node name is the empty string that actually means \N but if a particular node name is the empty string, then it stays.

There was a published study, Wrangling Messy CSV Files by Detecting Row and Type Patterns by Gerrit J. J. van den Burg, Alfredo Nazábal, and Charles Sutton (Data Mining and Knowledge Discovery, 2019) that showed many pitfalls with parsing CSV files found on GitHub. They achieved 97%. It's easy to write code that slings out some text fields separated by commas, with the objective of using a human-readable portable format.

You can learn even more by allowing autofuzz to test your nice simple code to parse human readable files.

haha yes