Florin makes his case
I'm a Linux fan and a Notes developer, although I can't say I love Notes and Domino--they are a dream for the user but a nightmare for the developer. Here are some comments on a few points in your article that seemed to be incorrect statements to me:

First, the cost of switching from Windows to Linux is not much bigger than that for switching from one version of Windows to another, in my opinion. Finding replacements for all Windows applications, porting all internal applications, etc. is only a small part of the cost. This is especially true for huge companies, where the deployment in itself is the actual big cost, since installing OpenOffice instead of Microsoft Office on a fresh Windows or a fresh Linux machine is about the same effort. In fact, now that I come to think of it, the cost might be somewhat smaller with Linux, since it has better support for deploying applications on a network than Windows has, and it doesn't require special support for this from the application itself, as is the case on Windows. That could mean you actually have to install a lot less applications individually.

Second, every custom application you have--except those which are based on Microsoft technologies such as ActiveX, VB, programming with Office, etc.--should be easily ported. In fact, Java applications need no porting and C/C++ applications should not be easy but also not very hard to rework for a new GUI (Graphical User Interface). Besides, this can be done in two steps: switching to a cross-platform GUI lib on windows, maybe as new versions of internal applications are released, and then only recompiling and testing when the switch to Linux is planned to happen.

The ones based exclusively on Microsoft technologies are a risk anyway and should be thrown away as soon as possible. Switching to Linux is a good occasion to do so. Proprietary technologies are always a risk, because instead of depending on a public body of standardization, regulation or anything else, you must depend on the support of a company, which might potentially become your competition or otherwise have an interest in hindering your business.