HP is open sourcing WebOS, the mobile operating system acquired from Palm last year for $1.2 billion, and Enyo, the development framework for the OS. WebOS has been widely praised yet has struggled to gain traction, in large part because its app ecosystem has always been paltry compared to iOS, Android and even BlackBerry. Will open sourcing WebOS be enough to get more developers on board? Perhaps, but it’s not guaranteed.

If HP does this right, it could be great news for open source. Android is nominally open source, but it follows what’s referred to as a “delayed open source” model. Google creates each version of Android internally and secretly without accept community contributions or input. It releases the source for each new version of Android once it’s complete. The resulting product is technically open source, but goes against the spirit of open source (see: How to Spot Open Washing for more). Furthermore, Android relies on Oracle technology for which Google does not have a license, which is the cause for the ongoing legal battle between Google and Oracle. A true open source mobile operating system that doesn’t rely on technology controlled by Oracle will be a big win for the open source community.

But that might not be enough to save WebOS by attracting more developers. After all, we already have at least a couple truly open source mobile operating systems. MeeGo, backed by Intel, and OpenMoko, for example. Both have dedicated supporters, but neither has gained the sort of developer traction that Android, iOS and Windows Phone 7 have.

Then there’s Symbian, which many are writing off, but which still runs on millions of phones. Nokia passed Symbian off to Accenture recently, which plans to continue developing and supporting the OS. It may sound like a lame duck, but remember that SAP is concentrating on BlackBerry for its new app market, and is even considering supporting old Windows Mobile devices since so many of its customers are still using them. Legacy technology dies hard.

Beyond the open source issue, developers are already complaining about having to develop on too many devices, and about Android’s fragmentation. Do developers really want to add another operating system at this point?

And what manufacturers will carry WebOS phones? Nokia is deeply in bed with Microsoft at this point. Google is well on its way to owning Motorola Mobile. Samsung is building its own operating system. That still leaves a few options, such as HTC, and of course HP can manufacture its own phones, but the market is crowded.

But WebOS already had more traction than MeeGo and OpenMoko before HP started talking about killing the product off last summer. Developers I’ve talked to are impressed with WebOS and with Enyo. But there’s been some trepidation about developing for it. The BlackBerry platform is notoriously developer unfriendly, but WebOS has failed to surpass it in number of apps available. On the other hand, Windows Phone 7 has leap frogged both WebOS and BlackBerry largely on the strength of its developer ecosystem.

It’s also worth considering the fact that developing for multiple operating systems is getting easier thanks to frameworks like PhoneGap and Titanium. Adobe recently acquired PhoneGap and has submitted the project to Apache. If HP takes WebOS and Enyo to Apache, there could be the chance for some interesting collaboration around development.

Developers love WebOS, but have questions about its traction and longevity. An open source WebOS may be just what it takes to get more developers to take a leap and start building applications for WebOS, since it does already have more traction than some of the other open source options on the market. A lot of this will depend on the licensing and how well HP manages the community. HP has already lost some good will in the community by laying off much of the WebOS development team, so it will be an uphill battle. Having quality hardware will be a key aspect of consumer success and a signal to developers that WebOS is a viable platform.

WebOS is a great operating system with one of the best interfaces on the market. It doesn’t have the stigma that other open source operating systems have had in the past. Apple developers have said that WebOS is the only threat to Apple’s iPad franchise. As cloud, mobile and social continue to converge as the new model for doing business, we need great a choice of platforms, and the more open the better. Here’s to hoping that open source WebOS is a success.