It's been a bittersweet week in tech: in among the usual gadget joy we've encountered dangers, drama and a sad goodbye - but we'll start with a big hello, and that's going out to the Moto X.

Lots of people are excited to see the first fruits of Google's Motorola purchase and it seems that the big news - other than the various sensors we've already heard about - is going to be customisation.

As Michelle Fitzsimmons reports, "customers will be able to select the colour of their device, plus engrave a name or message on the back... consumers may even have the option to upload a photo for inclusion as a personalised default wallpaper". Or in Chris Smith's words, the Moto X "will be Born in the USA and designed by Y.O.U."

A zinger for Zynga

The other big X in tech is of course the Xbox One, so the departure of the Xbox division's president is very big news indeed. Don Mattrick, who's been head of Microsoft's interactive entertainment division for three years, is off to social gaming firm Zynga.

It's a shrewd move by Zynga and bad news for Microsoft, Marc Chacksfield says: "During his seven-year tenure, Xbox Live members rose from 6 million to 48 million - a phenomenal amount. Even though the Xbox One's announcement was fumbled, pre-orders are looking strong. This is not a man who was ousted, but someone looking for a new challenge."

He's chosen a big one, as Zynga has been shedding staff: according to a whistleblower on Reddit, the firm has a "culture of copying" and is "burning through money". "Zynga needs to prove its relevance and Mattrick is well placed to achieve this," Chacksfield says, but "Microsoft has lost a key cog in its future gaming machine".

Week in tech
The Don has gone (from Microsoft to Zynga)

X might also stand for X-tremely dangerous, and it appears that the latest Android flaw is just that: a flaw in Android versions 1.6 and higher means that 99 per cent of Android devices may be vulnerable. That's 900 million bits of kit.

Hugh Langley explains: "The flaw is down to the way Android app updates are verified, as developers are able to modify the code of an app update without breaking the cryptographic signature. In other words, it's easy for them to hack in and put some nasty code in an app on the store that appears perfectly innocent."

It doesn't affect the Samsung Galaxy S4, which suggests that a fix may be imminent for other Android devices.

Is that the time?

It's been literally minutes since Apple iWatch rumours swept the net, and as ever we've rounded up the most reliable and the most ridiculous ones for your excitement and delightment.

It's clearly A Thing - this week we discovered that Apple has applied to register iWatch as a trademark - but it's A Thing that nobody outside Apple knows anything about.

One thing's for sure, though: if and when Apple finally ships it, Samsung will have something awfully similar on sale shortly afterwards.

One thing Samsung hasn't copied so far is the Apple TV, but that might change: this week Samsung bought up Boxee, streaming media stalwart and inventor of the interesting if flawed Boxee Box.

As Marc Chacksfield suggests, while it's fun to imagine an Apple TV clone, smart TV integration is much more likely. "It is likely that Samsung will integrate Boxee's streaming systems into its next-generation of Smart TVs, rather than producing standalone products brandishing the Boxee name," he says. "Boxee has been working on a cloud storage service that Samsung will no doubt be interested in using as well."

Farewell to the mouse man

Have you used a computer in the last 40-odd years? Then it's time to raise your mouse to Douglas Engelbart, who died this week aged 88. Engelbart is most famous for inventing the mouse, but his 1968 "mother of all demos" was even more important.

Week in tech
Douglas Engelbart, who died this week, helped invent computing as we know it

As the New York Times reports, in a single one-hour presentation "Dr Engelbart demonstrated the power and the potential of the computer in the information age" - not just the mouse but hyperlinks, video conferencing and WYSIWYG editing too.

The demo inspired the people who would go on to create many of the technologies we depend on today, and with Engelbart's passing the world has lost a true visionary.