Thanks for your answer, Mithrandir. I suppose I'll have to work out another solution or code this feature myself.

I've searched this forum and checked the FAQ over at Digicomplex, but I think what I want is too specific.

The intranet I'm currently developing is to be used by several organizations, as well as a webmaster supervising the lot. I'd like one user for each organization to be able to add and modify users for his organization only. What you get is something like:

Admin (supervising all)
|
+- Subadmin organization A
| |
| +- User A1
| +- User A2
| +- ...
|
+- Subadmin organization B
| |
| +- User B1
| +- User B2
| +- ...
|
+- Subadmin organization X
| |
| +- User X1
| +- User X2
| +- ...

I hope it's clear what I'm looking for, and that it is possible in the first place.

I've tried making a separate group with admin rights to the 'modify user' config, but then the user in this group can view/edit/delete all registered users.

Thanks in advance for your help!

In addition to what's already been said: XOOPS uses tables extensively for layout. If you want to revamp XOOPS to be XHTML compliant _and_ ditch tables-for-layout, then you'll have quite a job ahead of you. It can be done, though (I've done it for an intranet site), but requires some serious template coding and sometimes PHP-hacking.