“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, H.P. 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.

Mr. 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. Mr. Mercer said that 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. There were neither the right leaders nor the right engineers to do the job, said this person, who declined to be named because he still had some ties to H.P.