So you could have an emacs that... wasn't extensible. Seems pointless. Not that this hack has a lot of point either (a world class editor on a platform without a development toolchain?). Still, more pointless I guess.
Terminal IDE and AIDE for Java. SL4A for Python, JavaScript and Ruby. Ruboto. There's a version of Octave now. And I'm sure there's more besides. There are definitely development options on an Android device.
I've been using SL4A and the Jota editor to teach myself Python (professionally, I'm a .Net developer) on my Nexus 7 and I've been pretty happy with it. I can carry it everywhere, and anytime I have a few minutes to spare I can open up the ebook I've been reading, then go to the editor and/or the immediate window and try some things out. And if I'm at my desk, I can use a hardware keyboard, making things even easier.
Emacs improves the possibilities even more. At the very least, it's a far better editor than any of the current editors (unless you're a vim fan using Terminal IDE) for any scenario where you need an editor.
At best, it could get a whole package management system of supporting utilities that are available to it inside its terminal, and becomes a good way to develop with virtually any language that has a compiler that can be ported to Android. Maybe it even gets w3m browser mode, music player mode, and other awesome Emacs-as-OS features.
I meant there's no standard toolchain. Specifically there's no straightforward way to develop a vanilla Android app in Android. It's not self-hosting in the same way that "real" platforms are; until that is fixed, porting development tools in isolation isn't going to amount to much more than an amusing curiosity.
> Specifically there's no straightforward way to develop a vanilla Android app in Android.
How is what you want different from what AIDE offers?
With AIDE, you develop an Android app more or less like you would in Eclipse, and it compiles it and installs it into the system like any other Android app. It's in your application list, and you can run it like any other Android app.
How many different ways do you need to be told what to use to develop Android apps on Android? AIDE and TerminalIDE can be used to develop Android apps from start to finish including signing and the whole ball of wax. You can even open up your Eclipse projects and just pick up from where you left off.
I fixed the C-w issue by training myself to always close windows using it (for a while in the Gnome 2 days I was using a custom metacity theme with no title bars or buttons at all). The mode switching goes into your muscle memory and your body starts to recognize the difference between editor and GUI context.