Windows Phone 8 is well over a year old now, yet until recently we knew very little about Windows Phone 10.
Originally it was expected to be with us by the end of 2013 as it was thought that Microsoft may adopt the annual software cycle made popular by Apple in an attempt to keep its mobile OS fresh and, more importantly, relevant.
That didn't happen, but from the information that we've been able to gather so far it looks like Windows Phone 10 could be a massive overhaul, in fact it might not be Windows Phone 10 at all, but instead just Windows 10, as Microsoft is seemingly looking to unify its operating systems, so it's not surprising that it's taken over a year.
However we did recently get Windows Phone 8.1 to tide us over, while leaks highlight that Windows Phone 8.5 may also be on the cards and Microsoft is expected to reveal Windows Phone 10 at an event on January 21.
Before we get our teeth in Windows Phone 10 we need to visit the rumors surrounding version 8.5. It's been confused with the ninth iteration of the platform before, and it's important to make a distinction between the two.
Windows Phone 8.5
It looks like there might be such a thing as Windows Phone 8.5 in the works, but details are slim on the ground. All that's really known so far is that there will seemingly be some potentially quite substantial changes to the Start screen interface in Windows Phone 8.5, but there's no word yet on what form those changes may take.
It's also worth noting that while we list this as a Windows Phone 8.5 feature it's entirely possible that it may end up in Windows Phone 10, especially as so little has been said about Windows Phone 8.5.
Now we've got Windows Phone 8.5 out of the way we can get back on the Windows Phone 10 trail.
We're scouring the web everyday to bring you all the latest on Windows Phone 10 and we'll be constantly updating the information below to give you the best picture of what's to come.
Windows Phone 10 release date
Early rumors pegged Windows Phone 10 for 2014, but that's been and gone and we're still on Windows Phone 8.1. More recently a leaked document mentioned dates of between Q2 and Q3 of 2015, which covers April-September and that's just for a preview build, so the final release might be even later.
That's now looking almost certain as Windows 10 has been announced and is expected to launch this year and it seems that this will be the basis for Windows Phone 10.
While we might not see a final build of Windows Phone 10 for many months yet it looks like Microsoft is starting to prepare for a launch, as according to WinBeta it's been sending builds of Windows Phone 10 out to select partners, though apparently it's an old version with little in the way of new features.
Microsoft has also created an app called 'Phone Insider', which appears to let Microsoft employees test out the new OS. Hopefully it will be opened up to the general public soon though.
We also may have heard about one of the first Windows Phone 10 handsets- the Microsoft Lumia 940.
Windows Phone 10 or just Windows 10?
For a while we've been seeing reports that suggest Microsoft may look to ditch the divide between its smartphone platform and the one it uses for tablets and PCs - rolling them all into one tidy bundle called Windows 10.
It now seems that's exactly what's happening, as with its announcement of Windows 10 Microsoft claimed that the OS would work on screen sizes ranging from four to 80 inches. Not only that but the company specifically stated the Windows 10 would be the next version of Windows Phone.
Whether that means it will just be called Windows 10 or whether it will still be called Windows Phone 10 isn't clear, but either way it should be heavily based on the desktop operating system. Hopefully we'll have a better idea of both what it's called and how it looks after Microsoft's January 21 press event.
Windows Phone 10 features
Murtazin gave some early insight into the design of Windows Phone 10. Saying that apparently it will be a complete overhaul which will remove the tile based Metro interface that Windows Phone is currently known for.
Murtazin went on to say that the interface would be more influenced by Android than iOS. That makes sense, given the general overhaul, since we now know that it will apparently be based on Windows 10, and cross-platform app code compatibility.
Exactly how Windows Phone 10 will look and behave is still unclear, as it's unlikely to be identical to the desktop version, but there'll obviously be unity between platforms and a similar design language.
However given that Live Tiles are still a part of Windows 10 it may not look a million miles from Windows Phone 8, especially as Microsoft will only need the touch focused element of its new OS on phones.
But even so, as a version of the desktop operating system it could well be more powerful and versatile than Windows Phone 8, which could be where Murtazin was coming from in saying that it will be more like Android than iOS.
More recently we've heard from sources speaking to The Verge that its interface will be designed to fit with both Windows 10 and the Xbox One and that Windows Phone 10 will be a combination of the Windows Phone of old and Windows RT.
A unified app store
Windows 10 is bringing Universal Windows apps with it. The idea with them is that there will be a single app store across all Windows 10 devices, whether servers, desktops or (presumably) smartphones. However the smartphone bit hasn't been confirmed yet, so Windows Phone 10 may or may not share an app store with the rest of Windows 10.
Windows Phone 10 devices list
One of the big issues with Windows Phone 8 was that you couldn't get it on your Windows Phone 7 handset, instead you were lumped with Windows Phone 7.8.
It's thought that Windows Phone 10 won't be so restrictive, with Windows Phone 8 users in line to get the upgrade which means you shouldn't have to worry about picking up a Nokia Lumia 1520 or HTC 8X.