It seems probable our client will cancel the project we've been working on for 15 months.
It's possible (although not very likely) that it will get restarted at some point.
We've also extended our company's product in several areas while doing this. Other project teams may need to make similar extensions, and we'd like them to be able to make use of what we did.
So, what are the key things to record for posterity, so that a future team (which may include different personnel) can learn from what we've done?
This is slightly different from what to record for future maintainers, since people will probably arrive with little/no familiarity with our project, and will probably not have any extended involvement with it.
So far, we've worked on collecting information about each major feature/extension - so there's one place to look for requirements, pointer to the source code, test cases, etc, and are adding some narrative on key design points/decisions etc.
What else should we be doing and capturing, while the project team is still together?