Office Suite from Micro Soft.
Ms Word, Ms Excel, Ms Power Point, etc.
Ms Exchange is separate.
These apps were great a long time ago. I loved Ms Word for DOS! And Word and Excel were great on the Mac before Ms Windows (I bought Excel when it was Ms Multi Plan and Ms Chart).
But the passing of time just makes them fatter and slower, with few features that anyone needs. (Joel Spolsky would disagree with the Bloat Ware label.)
And the closed binary format, pointlessly tweaked whenever possible to fight compatibility from competing products, is quite annoying.
Feb'2008: Joel Spolsky gives some insights and workarounds
I rarely use Ms Word anymore, doing all my writing in EMail and Wi Ki.
Ms Excel is still useful, though I rarely play spreadsheet-jockey anymore. And I'm playing with Star Office/Open Office for my meager needs.
Competition: IWork, Open Office