

The best thing it it is completely free and there is a Mac version you can download. It does take about 30 seconds to load, though. Open office works great and will open up microsoft word, powerpoint, and excel files with no problem. PS - Office for Mac will in no way slow down your machine.
To do so seamlessly you need MS Office for Mac, I'm afraid. From your OSX side you can "drag" your Windows Word docs right into OSX and open them with any of the above mentioned word processors.

One more thing - BootCamp in OSX allows you to install any copy of Windows that you own (and therefore MS Office). MS Office for a Mac works well but I found it disappointing that the bells and whistles don't LOOK like MS Office. To do this perfectly you will have to purchase MicroSoft Office for OSX (expensive unless your workplace offers you an employer version, then it is cheap like dirt). TextEdit and Bean will open MS Word files but not perfectly. Another free & excellent OSX WP is "Bean". In addition to everything said here - OSX TextEdit has plain text (can be configured to act much like Notepad) and rich text.
