So, you will have LOTS of hooks around the place?
Depends on what you mean with "LOTS". I honestly don't know how many will be required, but I can imagine it will land somewhere between 100 and 200. We'll see. Where to place the hooks will be the difficult part of the implementation. I plan on downloading the top 10 mods for PunBB and going through them, making sure they would be possible to implement as extensions. I will also ask you guys to help me out in finding locations that I might have missed.
Does that mean that my personal customisations can be gathered together into an extension, and when i need to upgrade I can just take the standard install and apply "my extension", and the upgrade is done?
Yes. You won't even have to "re-apply" your extension. Just upgrade your PunBB scripts. Sure, there might be the odd compability break, but in most cases, it will work without a hitch. There are also limits to what is possible with these extensions, but I will do my best to add as much flexibility as possible without having a hook on ever other line in the source
"Programming is like sex: one mistake and you have to support it for the rest of your life."