So here are my answers to the "reasons" not to buy open-source software.

Safe? Safe!?

Come on. Microsoft's products are infamous for not being safe. Vista was supposed to be soooo much more secure than earlier versions of Windows. I said that was nonsense when Vista was first coming out. And what do we now see? Why, this month alone, we see that there are critical flaws.

Three of the flaws could let information slip out if users visit malicious pages using IE, and with the fourth vulnerability, all you have to do is view a malicious e-mail with Windows Mail, and ta-da, you've just been hijacked. I hope you enjoy your PC being part of a botnet.

Richer set of application development tools

Really? The last I knew your choices were Visual Studio and ... ah ... Visual Studio. That said, Visual Studio is a heck of a development environment, but you are locked in to one vendor for all your development needs.

If you want to pick and choose your development tools there's Eclipse, IBM Rational's Jazz.net, Red Hat's JBoss, or, heck, if you insist on Microsoft .NET compatibility, give Mono a try.

Larger number of packaged applications available

You can have any application you want so long as it's from Microsoft. There are a few exceptions: Intuit's Quicken, Adobe's imaging and pre-press software and 20 different freeware programs to compress and decompress files. But Windows stopped being about software choice a long, long time ago.

If anything, the Linux and the open-source world has an embarrassment of software riches. You name the functionality, there's probably half-a-dozen different programs that can deliver it.

Desktop Linux Is Immature and Perhaps Unnecessary

Excuse me? Then why did Dell just start offering Ubuntu on three of its consumer systems? Have you looked at Novell's SLED (SUSE Linux Enterprise Desktop) 10? What about MEPIS 6.5? If you're serious about your desktop, then you need to take a long, serious look at today's Linux desktops.

Technical Support Costs Are Actually Higher than Microsoft.Net

I call FUD. I've yet to see a serious study that has proven this contention. I'll simply note however that Windows desktop must be patched every month and have its anti-virus software updated essentially daily for it to be safe.

I can leave a Linux desktop alone for months and it will be as safe as houses. You tell me which costs more to maintain.

Richer Layer for Application and Business Process Integration Middleware

Could have fooled me. Why then is it that the last I checked, JEE (Java Enterprise Edition), in both its official Sun version and the open-source versions like JBoss, is still owning the application server space?

And, funny isn't it, how all the talk about Web 2.0 development seems to focus on AJAX (Asynchronous JavaScript and XML) and not on anything out of Microsoft?

More Focused Commercial Technical Support from Microsoft

I don't see how. Yes, if you pick a hodgepodge of open-source development tools—one from column A, two from column B—you'll have more trouble getting support. If you stick with say, Interface21's Spring Framework, Sun's Java family of tools, or Red Hat's JBoss, what makes you think they're not going to support you?

Microsoft.Net Creates End-to-End Framework That Offers Lower TCO

Again with this? What's Java and JEE? Chopped liver? If you want an end-to-end framework for lower TCO, lots of companies will give it to you while trying their darnest to beat Microsoft's prices.

Microsoft Will Try to Convince Your CEO that You're an Idiot If You Do

Of course they will. It's what Microsoft does. But this is 2007, not 2001. Your CEO—really much more likely your chief financial officer or CIO these days—may not be able to tell Apache from Zimbra, but he probably already knows that open source is a viable contender for almost any IT job.

In fact, chances are your company is already using Linux, at the very least, in your servers. Marshall your argument for the software you think is best for your company and make your best pitch. If you do, you've got a decent shot of winning no matter what Microsoft tries to pull.