On the FontLab forum, I saw Adam Twardoch's post about
DeltaMachine. For those who don't know, it's a script/plug-in for FontLab 7 (based on Tim Ahren's publicly available theory works about interpolation tools), and it's developed by
@Vassil Kateliev.
I tried to reach Vassil via FB, but I guess that message ended up in the spam folder.

Hopefully, he will see the mention, because I see he is active here, but also hope that some other people might share their experience.
I am interested to know about functionality comparison between DeltaMachine and Font Remix Tools.
Also, is DeltaMachine already coded, just waits for the docs/user manual, or it's in the development stage?
And while we are here, a question about
TypeRig, also developed by Vassil. I can see that it has a lot of functions divided by the vertical tabs. Before I dive in, just wanted to check, what's the general scope of this plug-in (what help one should expect from it, maybe a few most useful options etc.), and what's the best way to get a grasp on using it? Are the functions self-explanatory, and I just have to experiment or there is a user manual.
Thanks!
Comments
Although TypeRig does a bunch of cool things, a significant chunk of its functionality is specifically useful for working with variable font development.
TypeRig is split in two parts, that are currently distributed together - the core lib and the GUI. The core you could use as any other API. It functions as a proxy to FL and glues together the two major parts of FL API - fontlab and fontgate. It also simplifies a lot the python scripting. As you might know FL API is extremely powerful, but very hard to understand - it took me three years of brute-forcing the app to just learn what api call does what action and how to combine them together for my needs. The TR core is semi-well documented (internally) and most stuff is easily understandable - one just needs to scan trough the code and see some examples to get it. The GUI adds additional functionality - it is a "Fontlab within Fontlab" - and most parts of it are self explanatory, Also almost every button has a tool-tip explaining its functionality - one just needs to experiment a bit to get accustomed with the workflow
DeltaMachine (DM) is just another GUI (sub-script) of TR. Comparing it to RMX depends on what you want to achieve and the functionality you are looking for. There are several RMX tools and you could say that DM is equivalent to RMX Scaler. Curve Harmonizer is already present in FL and Genius nodes are absolutely fabulous... so that part (RMX harmonizer) i did not need to implement. RMX Slanter is also not needed, as FL does excellent job in fixing the contours after slanting (adding extremes, deleting unneeded nodes and etc.. you know the drill
So back to DM: Yes - it is pretty much experimental, but... Yes - it is fully functional. How does it compare to RMX Scaler - it does pretty much the same but differently - at first it looks very user-unfriendly, but it shines in other aspects - it works with surgical precision. It is not made for you to scale your entire font (not that it cannot
For TR as a whole: It is stable with the occasional problem here and there, but one learns how to get along with it. Extensible documentation is not planned for now. I am currently refactoring large portion of the code + slowly preparing for transition to Python 3 (whenever that happens with FL, i must be ready
Many thanks for taking the time to write a detailed reply, this is very helpful!
TR and DM sound like very powerful tools so I will definitely dive into the matter and start to experiment.
Hopefully, people from FL will provide documentation or quick video tutorials on how to accomplish most usual tasks (particularly making small caps and numerals), as Tim Ahrens did explaining FRT modules with a-few-minute long video tutorials. Your amazing work on developing these tools definitely deserves that!