It sounds cliche, but I've found the yEd graph editor crucial in reading a Dostoevsky novel and keeping up with all the characters and their relations. Is yworks pretty much the only game in town when it comes to graph editing?
If you still have that graph somewhere, we'd love to see it. We're always curious (and sometimes surprised and astonished) what people create with yEd.
As far as competitors go, there are lots of other options, both in end-user applications for graph editing, as well as libraries.
For end-users it seems many stick with the first tool they really like and get used to its features, strengths, and idiosyncrasies (and from my experience there are many weirdnesses among those applications, including our own). Automatic layout may be a killer feature for our offering, though. As far as I know there is not much that can compare here (although for many people simple hierarchic or force-directed approaches may suffice and they might not need every option).
For library users it often comes down to a decision based on required features, cost, custom development effort, and target platform. I think we're well-situated for customers where cost is less of an issue, that have competent developers and require extensive customization (and support). It's not uncommon that D3 might be a better choice, depending on the requirements.
Thanks for the response! FWIW, I find nothing lacking in the application, but I'm working on an ipad and it seems a native app would be less constrained by the browser quality.
There is Gephi, which is very capable, though I've also found it frustrating to work with, particularly for graph editing. Interface glitches, unresponsive elements etc. quickly get in the way.
Development seems to have stalled somewhat, so I'm not optimistic that this has improved.
yEd is my default go-to graph drawing tool. I use it mostly for engineering diagrams. It's kind of incredible what you can make with it, and it's basically cross-platform and I use it on Windows and Mac OS. The graph layout engine is first class and it has a ton of options.
If you can get into the flow with it, and trust the layout engine (instead of foofing around with placing your own things) it's basically replaced visio for 99% of my team's diagramming.
