First of all, thanks to everyone who's helped me, if you're wondering what I've been up to, this is it, now available for trying out.
It's a program that lets people put together a fully-featured language teaching system to teach any language in any language. (Except the ones that are written top-to-bottom, I haven't done those yet.)
This may not be a big deal if you speak one common language and want to learn another, where there are already plenty of resources out there, but for learning or teaching in small under-served languages this could be really useful. It's software that attempts to fill all the vacant niches at once. It is completely free, for this and other reasons.
By fully-featured, I mean that it can ask written or spoken questions, it can accept written or multiple-choice answers, it can test you on individual vocabulary items, on accidence, or it can put together the vocabulary it knows to produce grammatical sentences for you to translate. It can of course use any script 'cos of Unicode, and the keyboard can be set to produce Fancy Foreign Letters. It is capable of full internationalization. It connects to the Internet so that students can join online classes, they can then download assignments and do them and the results are uploaded to the teacher's gradebook. Though I say it myself, it is pretty good.
That's what the end-users get. Mid-level users, either teachers or motivated students, can make their own vocabulary lists, quizzes, exams, textbooks, etc. And the highest-level users can write the plugins that lets the thing do the grammar.
Here's a demonstration of the sort of thing an end-user might get.
https://github.com/peachpit-site/downloads/releases/download/Win64-Turgan/Turgan.101.setup.exe(It teaches a made-up language (Turgan) because the conlang community are the ideal people to test the high-level features. I knocked this up for what they call a "speedlang competition" to show how much of an interactive textbook I could throw together over a couple of admittedly very busy weekends.)
And here's a version for high-level users, where you can edit everything. It teaches you how to use itself and includes demos.
https://github.com/peachpit-site/downloads/releases/download/Win64-Peach/Peach.setup.exeI'd appreciate feedback. The high-level version is set to update (having gained your permission) from the internet, so I can release changes immediately.
Shortly it will be open-source, there's still some gnarly stuff I want to refactor. (This will be the Fifth Great Refactoring, I've been quite good about cleaning my code base. But not good enough.)
When it's open-source, I would like to ask for some help. As you can see, the executables are Windows only. If anyone could help me do versions for other platforms, I would be very grateful. I know FPC/Lazarus is very good like that, that's one reason I'm using it, but the system has so many moving parts that it's not going to be simply a matter of cross-compiling and releasing and it's all going to work straight out of the box. I hope some of you can see how useful this thing could be, and how free and benevolent it is, and would like to pitch in.
I've set up a subreddit
https://www.reddit.com/r/peach4languages/ in the hope that as there are more interested parties they can gather there, and if some of you would like to post there and kick things off that would be nice.
Thanks! And enjoy!