I have MacOS 10.5 (Leapard) on an intel iMac and use Opera to access my roster (AIMS eCrew). However, Opera won't let me access the company on-line e-mail system so I use Safari for that. All a bit of a nuisance.
Now, that's at home - in my lodgings I have an older iMac running MacOS 10.4 (Tiger) and can run all aspects of eCrew, e-mail and most other things the company wants me to view. It's all beyond me so I just put up with it.
I went on to the AIMS help site once and it said that wireless internet connections are not supported - seems to work though!