Many of these "app killer" apps still have serious limitations that prevent any real traction. Thunderbird is a great email client, but has long lacked some of the features that Outlook has like appointment calendars, for example. Gimp is a very cool graphics application, and very powerful and completely free. It does, however, suffer from usability issues that conflict with it's peers like Photoshop, which is frustrating, and doesn't fully support importing Photoshop files, though pretty good, it does miss some random effects and other things when importing at times.
OpenOffice on the other hand, seems to be a very legitimate alternative to MS Office users. I use OpenOffice and have very few issues when working with clients that have standard office docs (without the "x" on the extension), and any I have had have been cured by sharing as open document format files. They looks and work pretty darn close to Office (pre Office 2007) so flipping between the two is easier as well.
It seems to me one of the more difficult aspects getting big business away from MS Office is the fact so many of them pay a huge licensing fee every year for access to a huge product line. SO switching to OpenOffice would save them little or nothing in these large license packages and add to that the complexity of yet another application to support for IT staff and training.
In the case of OpenOffice, they are not taking over, not because lack of features or usability, but, more because of simplicity and Microsoft large hold on business via bulk licensing fees.
If you are a small business or at home office, try OpenOffice, it's a very real alternative to MS Office, and free!
