Team Lotus
One of the few fond things I got when my old employer was borg'd by the big blue, was replacing MS Office with Lotus Symphony.
I actually quite liked the tabbed layout. It was the difference that browsers have these days vs opening a window per active document / site. That you could flick tabs between .docs, spreadsheets, into presentations etc. within the same window I thought was a really nice feature. Something I was hoping that big blue was going to bring to AOO when it axed Symphony, but last I tried it it was still application-window-per-document centric.
Biting the hand that feeds IT
