Previously it had to integrate into the forum... because the forum was king.
Now (or soon) MODx will be king and the forum will be doing the integrating. Using MODxvBIN, users will be lightly synchronised (i.e. they will exist for both and be logged in together, but all MODx pages will use MODx logged-in status to ensure relevant content is fed to each user).
Anyway. The requirements are really that users should be able to manage their own albums, add content to shared albums and view all other photos. I looked at maxigallery briefly, but felt it was rather for the site to host albums, rather than community sharing.
