You can not expect others give you ideas or solve practical issues pointing packages etc... That totally depend on the application and each application has different requirements. Not to mention that every time humans are involved you have to consider their ability to use the tool.
I'll give you a practical example.
This is an application I've recently ...
TeX and friends play a very important role on things I do. Let me see if I can talk about a couple of them.
I'm the coordinator of a small choir in a parish. I decided to come up with a personal songbook to help me on keeping track of songs we use during masses or processions.
The songbook is typeset in LaTeX with help of several packages, most ...