Question: A Multitouch Touchscreen Monitor for Apple Mac OS X
Having become familiar and comfortable with using a touchscreen to control phones (Android 4.4) and tablets (Windows 8.1 and Android 4.4), in 2015 I sought to bring a new lease of life to a retired 2008-vintage MacBook Pro by adding a multitouch monitor. Online research and pre-sales email conversations with candidate touchscreen monitor OEMs highlighted a dispiriting fact: Apple’s official line – “Touchscreens: iOS = Yes, OS X = No!" – has had a generally chilling effect on said OEMs (whose touchscreen monitors are designed for Windows 8 computers), in that, when it comes to adding one of their touchscreen monitors to an Apple Mac OS X computer, they range from uninterested via dismissive to woefully ignorant. It was only thanks to fellow OS X end users vividly showing what can be done, such as...
• 'Multi-touch Mountain Lion’, by diffractive – video, 1’13"
…that I persisted in achieving my own OS X multitouch monitor goal. Indeed, I'm actually adding this User Tip Contribution from an on-screen touch keyboard  on the touchscreen of my own Dell S2240T multitouch monitor, attached to a 2008 MacBook Pro running OS X 10.9.5 (video via DVI-to-HDMI cable, plus touch data via USB cable). So I’m posting here in the hope that other folk desiring 'A Multitouch Touchscreen Monitor for Apple Mac OS X’ in future may benefit from my discoveries, by finding this message during their own online research.
All You Need Is Love OS X Driver Software
The vital linking component is an OS X driver, which takes the multitouch events signals (arriving at the MBP’s USB 2.0 port from the Dell S2240T’s upstream USB 2.0 port, via the USB cable included with the Dell S2240T) and serves them up to OS X in ways that make the touchscreen work as a multitouch monitor. AFAICS, the world leaders in developing such touchscreen drivers (for multiple OS’s) are Touch Base  – and with their Universal Pointer Device Driver (UPDD) and ‘UPDD Gestures.app’ I’m enjoying what Apple seem to obstinately refuse to contemplate: OS X on a multitouch monitor, where all the familiar trackpad multitouch gestures just work on the Dell S2240T touchscreen.
As an aid to choosing touch-centric devices, Touch Base maintains a list which has been built up over their years of experience:
• Touch Device List @ Touch Base
To get the highest level of OS X trackpad-like usability on a touchscreen, you’ll want to scroll down to the list’s 'Touch Monitor – Multi touch’ section, and pick a ‘Manufacturer' and ‘Model' which has a blue-&-underlined link entry in the right-hand 'UPDD touch controller definition’ column. Doing so means that the Touch Base OS X UPDD + Gestures driver suite will work with said manufacturer’s model of multitouch monitor.
Universal Pointer Device Driver by Touch Base – Caveats
(A) Evaluation For Free – you’re welcome to try-before-you-buy, by ordering up an evaluation copy of UPDD from the Download Centre webpage (single touch) ; by email request, you can also try out an evaluation copy of Gestures (multitouch). Pre-sales email support was top notch.
(B) Multitouch Utility – while it’s true that OS X isn’t designed for touch (unlike Android or iOS, for instance), I’m finding that OS X is as easy to use under touchscreen control as the Windows 8.1 desktop environment (which isn’t touch-optimised either). Given that right-clicking, scrolling, task switching, etc., can occur using the same multitouch gestures on-touchscreen as Mac users are already familiar with from trackpad use, I’m very pleased indeed to have been able to transcend beyond a physical keyboard and trackpad .
(C) Cost – at the time of writing (Mon 30 Mar 2015) a single commercial UPDD licence costs £95.00 / $171.00 / €133.00, while the cost for a single home/personal/educational use UPDD licence is £57.50 / $109.00 / €90.00 (to which VAT must be added, as appropriate). So in the UK, I paid £57.50 + 20% VAT = £69.00 via PayPal invoice (see their ‘Prices’ webpage for details of bulk pricing reductions, means of payment, etc ). While this may seem pricey for a "mere" driver, IMHO it’s well worth the investment for the multitouch rich utility boost it brings, and just compensation for all the programming expertise that’s gone into so elegantly working around Apple’s obstinate ‘No OS X touchscreens!’ dogma.
So if you too would like to be using OS X on a multitouch monitor, I can personally recommend both the Touch Base OS X UPDD + Gestures driver suite, and also a Dell S2240T multitouch monitor (of course, other OEMs are also available: any other UPDD-supported multitouch monitor in Touch Base’s 'Touch Device List’ ought to work just fine, too).
 An on-screen touch keyboard – VirtualKeyboard by Vincenzo Corallo, 14 day shareware then $19.95 for new users:
 The world leaders in developing touchscreen drivers (for multiple OS’s) are Touch Base:
 Order up an evaluation copy of UPDD from the Download Centre webpage (single touch):
 Able to transcend beyond a physical keyboard and trackpad – of course, this is only an option and by no means a necessity!
• The only (slight) disappointment is that when both MBP and Dell S2240T multitouch monitor are in their respective low power sleep states, a finger tap on the touchscreen doesn’t wake the system up. So I’m currently using a old Belkin Bluetooth mouse for wake-up duty and occasional text selections, and I have a second-hand Magic Trackpad on order – since there are a few times when the familiar OS X multitouch gestures are easier to execute on-trackpad than on-touchscreen (for instance, when an on-screen finger obscures a helps-if-you-can-see-it detail, eg: text selection, or object-handle manipulation).
• Also, I hunt and peck (one-finger typing) rather than touch type, for which Vincenzo Corallo’s on-touchscreen VirtualKeyboard is proving to be Very Useful Indeed – but a typing-heavy touch typist user may still prefer to use a physical keyboard, wired or wireless, over its on-screen keyboard analogue; and since the two forms of keyboard input are not mutually exclusive, they could be mixed-&-matched on the fly.
 Touch Base’s ‘Prices’ webpage:
MacBook Pro (17-inch Late 2008), OS X Mavericks (10.9.3), Apple A1189 battery - dead