What about in-app purchases? Why not a set of free in-app "purchase" options for large sets of these packages?

In-app purchases can be used to trigger your application to download new data, but not new executable code.

The packages are text files, not executables.

Exactly, so all you could do is trigger certain bundles to be 'unlocked': you would always have to ship them.

You could use a virtual machine library (if anything suitable exists) and run everything inside one executable - it would probably have horrid performance but you get rid of the single binary restriction. You can put on a nice front-end and tell the user how much longer he has to wait until the operation is complete.

Virtual machines are generally prohibited by the guidelines as well. (Exceptions exist for things like script interpreters, which need to be present for some games to run, e.g. Lua.)

I think the difference here is between interpreting scripts that come with the binary, and downloading new scripts from the internet (or other untrusted locations). The latter is prohibited.

To get around it, you'd have to make it In App Purchases, because these also come from a the App Store.

So the issue here is not that the TeX codebase is messy, but that it doesn't conform to Apple's App Store guidelines, right?

So, go with LuaTeX ;-)

I never understood the exception for game engines (ala Lua). Why are those okay but other VMs not okay (from Apple's perspective, of course)?

Apple wants to restrict the platform options available to preserve their user lock-in. They were sort of forced to make an exception for games because they had no alternative to offer.

They don't want to have other platforms inside their platform because they think it would result in a bad user experience.

You can't do very much within those guidelines, can you?

Totally, that's why there are hardly any apps for iOS, and the paying market is such a fraction of that on Android.

It seems the cult of Apple is touchy today and can't detect a joke. I'm sorry if I have inadvertently hurt your feelings - I will be sure to clearly state my humorous intentions next time. </humour>

For the record, I do not own devices based on iOS or Android and I don't care for your little Apple-Google feud with which you seem to be so concerned with. So please, carry on with those market statistics about Android, I am dying to know more.

This ad hominem kind of scrawl is inappropriate for HN.

I get carried away from time to time, sorry about that. No offense meant.