Or indeed, wither Zimbra? Microsoft has officially launched its acquisition bid for Yahoo for $31 per share, valuing the company at $44.6bn (you can read the offer letter here). It’s a sign of my open source-focused view of the world (and the fact that I was using the software at the time I heard the news) that my first thought was “what does that mean for Zimbra?”.

Yahoo acquired the open source software vendor for $350m in September last year to expand its hosted mail and collaboration capabilities. It probably goes without saying that Microsoft isn’t going to want to maintain an open source alternative to Exchange, so would Microsoft set it free or take the opportunity to crush it like a bug?

Will it be Dr Jekyll or Mr Hyde? I know what my money’s on.

Meanwhile, over at the Guardian, Charles Arthur takes a look at the practical (rather than philosophical) open source-related problems of merging Microsoft and Yahoo:

“Yahoo’s servers, answering billions of page requests every day, use a web system called PHP to generate customised pages. Microsoft doesn’t like PHP… Integrating Yahoo into Microsoft would mean either tearing out PHP and replacing it with ASP, a huge project that would be enormously expensive while bringing no visible benefit to users, or require Microsoft to accept an open source product deep within its new property. Neither is palatable; if Microsoft dogma is followed, it will throw out PHP. Watch out for the reliability of Yahoo if it does,” he writes.

That simplifies things somewhat, especially given Microsoft’s partnership with Zend to improve the performance of PHP on Windows. I’d guess that Microsoft could live with being seen as a PHP user. Could the same be said of Linux and FreeBSD?

“Take the giant part of Yahoo, its mail servers. Those run on a free, open source operating system called FreeBSD,” adds Arthur. (It’s news pages are on Linux, while my.yahoo and the homepage are also on FreeBSD). “migration from one platform to another is the sort of task that gives chief information officers sleepless nights and ulcers. Interestingly, Microsoft did exactly this with Hotmail in summer 2000. Can it repeat the trick in 2008-09?”