Actually doing the port is only a small part of the problem. Having done it, it needs to be tested, and that means volumes of test scripts and packages that need to be created and maintained. Once it's been tested to the level where it's product-worthy, then all the documentation, all the training of support staff, and all the other tasks needed to run a program into a saleable product need to be done. Fred Brooks (the Mythical Man Month, (Addison Wesley, ISBN 0-201-83595-9, 1975) pointed out all those years ago that it takes nine times as much effort to create a programming system's product as it does to make a working program.

2. iNotes support is available for Linux users with Domino 6.x
Lotus says that from Domino 6.0.2, Linux is supported as an iNotes Web Access client via Netscape 7.0. The argument is that if Netscape 7 can support iNotes Web Access on Linux, then pretty much any Domino and Notes application can be supported on Linux. So why is a client needed at all? If people can get a mail client application on Linux that's this good, it solves a large chunk of the client need, thus making it harder to justify the client investment to port to Linux.

It's a good argument, to my mind, and for quite a few customer companies, it could be a compelling argument. It helps build Linux market share, which is the next point.

3. There isn't a market.
If there were a market big enough for Lotus to make a profit and a decent market share in selling Linux Notes client licenses, they'd be doing it by now. Having done the server port, as I said in point one above, Lotus should know exactly what the effort and cost of the client port is. I can't believe that they haven't done that analysis in some detail and that they don't revisit it on a regular basis. So the fact that there isn't a native Linux Notes client product now tells us that in Lotus's opinion, there isn't a market yet, or at least, not when the port would be done.

I've heard a suggestion from sources in IBM that the company feels that the window of opportunity for a Linux client port is past. It would take 18 months to do the port, and by the time it's done, nobody would want it any more. That certainly was what happened with the Novell NLM Notes server in the V4 timeframe, and I suspect it also happened with the old Unix clients for Notes. Lots of clamor for them, followed by little take-up when they appeared. This all happened way back in the mid '90s.

But a large part of the reasoning for that was that Windows NT appeared with better server OS for client/server applications than Netware, because it has proper multitasking. Windows 95 appeared in the same timeframe. Whatever you might think now about Win95, it was a whole lot better than Windows 3.1, and good enough to stop any large-scale Unix desktop rollouts at the time. But will Linux be in decline in 18 months time? I don't think so.

4. Notes works under Wine.
Wine is an implementation of much of the Windows API on Linux. See http://www.winehq.com for more information, and in particular, read http://www.winehq.com/?page=why, which discusses the whole reason for Wine's existence. The core argument is that until there are more core business applications like Notes available for Linux, people won't move to Linux. So tools like Wine aim to lower the bar by making Windows applications available on Linux. Linux market share increases, so vendors are encouraged to do native Linux applications. Indeed this may be the reasoning behind Lotus's "support" for Notes R5 under Wine; every little bit helps.