The 25th of October is an auspicious date on the Microsoft calendar. It's not just the date Redmond intends to release Windows 8; it's also the same date that Microsoft released Windows XP, back in 2001.

Here's another big date, only slightly more ominous: 8 April, 2014.

That's when, if you're still running Windows XP, you had better have a good back-up plan or lots of money to give Microsoft if you want to keep secure. When that first week of April comes to a close, extended support for Windows XP will finally come to an end.

What to do? This October has also seen the launch of another operating system, one which hopes to capitalise on the end of Windows XP and the uncertainty of Windows 8.

That operating system is Ubuntu 12.10, and Canonical reckons it has been talking to some big customers about using Ubuntu as a desktop replacement for PCs on Windows XP before they migrate to Windows 7 – as many are doing now that Windows 8 is nearly here.

"From our perspective, that [Windows 8] means a lot of users considering their desktop platforms," Canonical vice president of products and communications Steve George told The Reg just before Thursday's Ubuntu 12.10 release.

"We are spending a lot of time talking to enterprise and corporate customers about their next platform."

One of the biggest potential customers is the UK government. Canonical has been lobbying hard for Whitehall to use PCs running Ubuntu.

But George won't specify who Canonical is talking to. "We are very supportive of the Cabinet Office's drive to open source," is all he would say.

Microsoft partners with whom The Reg has spoken have told us that only now, three-plus years after the release of Windows 7, are they getting the massive demand for Windows 7 they had so long been anticipating.

Walker White, chief technology officer of IT asset management specialist BDNA, reckons his company is now working on five of the seven largest Windows migrations in the US - which include a major government entity with 450,000 PCs and a well-known financial institution with 250,00 PC all currently on Windows XP.

"We are just seeing a peak now, one-and-a-half years before the end-of-life of Windows XP," White tells The Reg.

The UK government is among those finally jumping. NHS Scotland, not an BDNA customer, just announced 100,000 Windows XP machines are going Windows 7, and renewing the health giant's lapsed Enterprise Agreement with Microsoft.

BDNA's financial customer, which is migrating to Windows 7, must replace or re-write 1,500 of 2,200 apps that have been written for Windows XP.

One of the biggest sticking point for any mass operating system upgrade is the apps, and that's been one reason so many Windows XP users have been holding back - because their Window XP apps rely on Windows XP's browser - Internet Explorer 6 or 7.

BDNA's financial customer, which is migrating to Windows 7, must replace or re-write 1,500 of 2,200 apps that have been written for Windows XP. The corporation is just two-and-a-half months into the migration.

Such examples are common in the UK, especially in government, which is heavily dependent on Windows and locked into IE 6 and 7 from the top down.

Moving from Windows to Windows is bad enough then, but Windows to Linux?

On Linux, Canonical reckons it has the answer with that hoary old favorite, Windows Terminal Services. Ubuntu 12.04 LTS, released in April, introduced remote desktop protocol using Freerdp, the open-source implementation of the Windows RDP protocol released under an Apache license. Freerdp enables Ubuntu to work with desktop thin-client services from Citrix and VMware.

12.10 has also added a remote login option, so users connect to their RDP server from the greeter screen. Canonical says you can embed applications like Excel in the launcher and get straight to your app without needing to first log into terminal services.

Canonical works with Microsoft on RDP with participating Linux devs and those working on Freerdp participating in Redmond developer events such as plug fests. Freerdp has been updated to work with Windows 8 and Windows Server 2012.

Meantime, Canonical has given the big shops, including those in government, extended support time – from the usual three years in an LTS to five with 12.10 LTS.

Critical mass chicken and egg

The idea is to keep refining terminal services and the hardware support, with government reaping the benefits, says Canonical.

"Our developers are aimed at the enterprise - working on great hardware support, [and a] stable operating system," George said. "The more popular Ubuntu is, and the more OEMs we work with, the more features come in and the more polish we have."

The challenge for Canonical and Ubuntu is to build the kind of groundswell that entices OEMs to work on Ubuntu, improving it and - in turn - convincing users currently wedded to Windows XP to move to Linux, which goes on to attract even more OEMs to the distro.

It's often said that Microsoft's biggest competitor is itself, thanks to the inertia of users on existing versions of its software. Canonical would claim it now offers an alternative to the increasingly predestined Windows 8 get-out route of Windows 7.

Canonical, as founder Mark Shuttleworth likes to tell us, sees itself as the choice for Windows converts looking for an alternative to Apple.

But with big government sectors like NHS Scotland switching back to Microsoft, the Linux camp will have to make the most of its lobbying. It'll also need to convince people that terminal services, stuck with a reputation for delay because such systems must call remote servers, is the future for desktop apps too expensive or time-consuming to rewrite and which cannot be webified. ®