Hello,
I was working as a teacher, I and my friend wanted to give offline wikipedia content to children using tablets. We stumbled upon OpenZim format.
After some work over the past two weeks. The tool is finally ready and live at http://www.srik.me/zimbalaka
You can read about it here http://www.arunmozhi.in/blog/zimbalaka-an-openzim-creator/
The source code is at https://github.com/tecoholic/Zimbalaka.
Kindly take a look and I would be happy if people could host it in multiple places in use it, since current hosting on a friend's server ;)
Regards,
Arunmozhi