If you mean can you write something using Microsoft Works word-processor - and open it using OpenOffice - yes you can ! OpenOffice will happily open .wks files.
Yes - Microsoft Publisher can open Microsoft Word files without any problems.
Apache Open Office KOffice Google Docs Neo Office LibreOffice but Open Office at 4.1 seems to be the best I have used(using Now)
Yes it is.
Open Office will happily read Word perfect documents.
There ain't many disadvantages.The application takes a while to start up.There is no program comparable to Access in Open Office.
Using an open office layout in businesses takes away the isolation of individual offices - maintaining a sense of 'belonging'.
It would depend what the 'something' was.
Open Office uses far less resources (disk space, memory etc) than Microsoft - so, if you're using a netbook - you'd be better off with Open Office.
Save the document using the 'save as' function (instead of the normal save) - then select the appropriate format from the drop-down menu.
You mean run them at the same time? Sure, why not. I haven't used either in a while, but you can open files created in either suite with the other one, but you usually have to save the MS Office file using an older file format that Open Office can understand. I've done it before flawlessly. The only thing I've noticed is that the formatting might look slightly different in Open Office, but goes back to normal in MS Office. By now, the latest MS Office should be backwards compatible with Open Office, but read the documentation. Better yet, when you save a file in MS Office, save it as you would a normal file. Then save-as and choose the older file format, e.g. MS Office 2007. Open both up in Open Office, and see if you get a prompt. If they both open up fine, you're good to go. I don't think there are really any problems with Open Office files opening in MS Office. The open-source community is really good at making sure Open Office files can be read using MS.
Open Office works extremely well with Windows 7 ! I've been using Open Office since version 1.2 came free on a computer magazine's cover disk years ago. Never had any problems with it - despite having changed Windows version twice, and am now using Open Office version 3.4
Assuming you mean word-processing software : Microsoft Word, Ability Write, Word Perfect, Open Office Writer, Lotus Word-Pro, Microsoft Write.