The TouchPad tablet from Hewlett-Packard was one of the most closely watched new gadgets of 2011 — and quickly turned out to be the year’s biggest flop. The TouchPad, which was supposed to be a rival to Apple’s iPad, lasted just seven weeks on the market before HP killed it, citing weak sales.

Analysts point to a long list of factors behind the tablet’s quick demise. But some of the people involved in creating the tablet’s core software now say the product barely had a fighting chance.

That software is called WebOS, an operating system built on the same technology used by many Web browsers. It promised to be more flexible and open than Apple’s tightly controlled iOS software, and more beautiful than Google’s sometimes wonky Android system. HP acquired Palm, the maker of WebOS, for $1.2 billion in 2010 so it could use the software in products like the TouchPad.

WebOS turned out to be something of a toxic asset. Several former Palm and HP employees involved in WebOS say that there was little hope for the software from the beginning, because the way it was built was so deeply flawed.

“Palm was ahead of its time in trying to build a phone software platform using Web technology, and we just weren’t able to execute such an ambitious and breakthrough design,” said Paul Mercer, former senior director of software at Palm, who oversaw the interface design of WebOS and recruited crucial members of the team. “Perhaps it never could have been executed because the technology wasn’t there yet.”

The WebOS story also illustrates how hard it will be for anyone to mount a serious challenge to Apple and Google when it comes to mobile operating systems. Those two companies have won dominant market shares and the allegiance of thousands of app developers. Many other companies have chosen Android for their phones and tablets, but this ties them closely to Google and makes it hard to stand out in the crowd of Android products. By owning WebOS, HP could control both the hardware and software and gain a more direct relationship with customers.

And Palm’s sales pitch was that because the operating system was based on common Web technology, it would be easier to create software for it, which would attract programmers to make WebOS apps.

But WebOS had problems from the start, when Palm first created it for the Pre smartphone, former Palm employees say.

Mercer was well known in the design world for his contributions to several of Apple’s most important products, and Palm recruited him. After some internal debate, the company chose to have WebOS rely on WebKit, an open-source software engine used by browsers to display Web pages. Mercer said this was a mistake because it prevented applications from running fast enough to be on par with the iPhone. But a former member of the WebOS app development team said the core issue with WebOS was actually Palm’s inability to turn it into a platform that could capture the enthusiasm and loyalty of outside programmers.

From concept to creation, WebOS was developed in about nine months, this person said, and the company took some shortcuts. With a project like this, programmers typically start by creating the equivalent of building blocks that can be reused and combined to create different applications. But with WebOS, Palm employees initially constructed each app from scratch. Later, they made such blocks, but they were overhauled once by Palm and then again by HP, forcing programmers to relearn how to build WebOS apps.

Another issue was recruiting. In 2009, it was hard to find programmers who had a keen understanding of WebKit, Mercer said, and Apple and Google had already snatched up most of the top talent.

Palm put itself up for sale in April 2010. It soon attracted HP, which hoped to use WebOS to accelerate its smartphone and tablet efforts.

But as HP absorbed Palm, important members of the WebOS team were disappearing. Mercer was already gone, having lost confidence, he said, in WebOS’ future. Peter Skillman, vice president of design at Palm, eventually left for a job at Nokia. Matias Duarte, vice president of human interface and user experience for WebOS, left a month after the acquisition for a job at Google. Several people said his departure was a major loss. “He was WebOS,” the former member of the WebOS software team said of Duarte. “When he left, the vacuum was just palpable. What you’re seeing is frankly a bunch of fourth- and fifth-stringers jumping onto WebOS in the wake of Duarte’s leaving.” Duarte did not respond to a request for an interview.

The TouchPad shipped in July, months after Apple released the iPad 2, which was significantly thinner and faster, for the same $500 price tag. The new tablet got lukewarm reviews. “There’s no more guaranteed way to make something feel like a train wreck in slow motion than to make it run like it’s a train wreck in slow motion,” Matt Buchanan of Gizmodo wrote.