Facebook has announced a second mobile talent acquisition in two days as the company bought Strobe, the maker of a platform supporting mobile web apps that can work on multiple devices and operating systems like iOS and Android.

The company’s founder Charles Jolley was behind Sproutcore, an open source Javascript framework that lets developers create web-based applications that resemble native desktop experiences. He also designed the architecture behind MobileMe’s web-based applications at Apple. Facebook said Jolley will join the company’s mobile engineering team.

His company Strobe, which raised $2.5 million from O’Reilly AlphaTech Ventures and Hummer Winblad, lets developers test code for mobile web apps and manage their deployment across multiple platforms from a single interface. It also comes with analytics to track usage.

The deal to buy Strobe plays into a big push this year to get developers building HTML5-based mobile web applications instead of native ones for the iOS or Android platforms, which Facebook doesn’t have as much power to influence.

After several months of anticipation, Facebook launched an HTML5-centric platform last month that enables mobile developers to spread their applications virally — which is something the native iOS and Android app stores aren’t really designed to do because they’re directory-based and curated (especially in Apple’s case.)

Given the critical moment Facebook is at in terms of building credibility with mobile developers, the venture funding that Strobe raised and the experience of the team, the price on this deal was probably significantly higher than the one Facebook announced yesterday to buy photo app maker Digital Staircase.

Strobe announced the deal on their company blog:

We’re happy to announce that, as of this week, the Strobe team is joining Facebook!

Strobe was founded on the belief that HTML5 can transform the way average people use their mobile phones through apps that are available everywhere, anytime, on any device. Now we’re joining the talented people at Facebook to help develop innovative mobile experiences for their users around the world.

For now, the Strobe service will continue to be available to existing users in its existing beta form. We will provide updates by email if and when this changes. SproutCore, meanwhile, will continue as an independent project.

Strobe has been a fantastic adventure. Thank you to everyone who has supported us. We look forward to working with you again in our future roles.