People have been asking, so here goes.
- Works with really large textbases without performance loss, yes.
- Windows cross-browser testing indicates compatibility with IE6, Firefox 1.0+, Opera 8. Netscape has yet to be tested. Konqueror has yet to be tested. Mozilla has yet to be tested.
- Mac cross-browser testing indicates compatibility with Firefox 1.0+, Safara 1.3.1, Camino 0.8.4.
- Mac IE5.2 does NOT work, but is on the to-do list.
- Downlevel browsers (Netscape 4, IE4) will probably choke and die. May flights of angels sing them to their rest. Okay, they won't die, stop crying, but they won't support AJAX Index Popups.