Focus in future will be on HTML5 as mobile world shifts towards non-proprietary open standards – and now questions will linger over use of Flash on desktop

Mobile Flash is being killed off. The plugin that launched a thousand online forum arguments and a technology standoff between Apple and the format's creator, Adobe, will no longer be developed for mobile browsers, the company said in a note that will accompany a financial briefing to analysts.

Instead the company will focus on development around HTML5 technologies, which enable modern browsers to do essentially the same functions as Flash did but without relying on Adobe's proprietary technologies, and which can be implemented across platforms.

The existing plugins for the Android and BlackBerry platforms will be given bug fixes and security updates, the company said in a statement first revealed by ZDNet. But further development will end.

The decision also raises a question mark over the future of Flash on desktop PCs. Security vulnerabilities in Flash on the desktop have been repeatedly exploited to infect PCs in the past 18 months, while Microsoft has also said that the default browser in its forthcoming Windows 8 system, expected at the end of 2012, will not include the Flash plugin by default. Apple, which in the third quarter captured 5% of the world market, does not include Flash in its computers by default.

John Nack, a principal product manager at Adobe, commented on his personal blog (which does not necessarily reflect Adobe views) that: "Adobe saying that Flash on mobile isn't the best path forward [isn't the same as] Adobe conceding that Flash on mobile (or elsewhere) is bad technology. Its quality is irrelevant if it's not allowed to run, and if it's not allowed to run, then Adobe will have to find different ways to meet customers' needs."

Around 250m iOS (iPhone, iPod Touches and iPad) devices have been sold since 2007. There are no clear figures for how many are now in use. More recently Larry Page, chief executive of Google, said that a total of 190m Android devices have been activated. It is not clear how many of those include a Flash plugin in the browser.

At the start of 2011, around 20m devices had Flash in the browser, Adobe said, and it expected that by the end of this year the total would be 200m.

"Our future work with Flash on mobile devices will be focused on enabling Flash developers to package native apps with Adobe Air for all the major app stores," Adobe said in the statement. "We will no longer adapt Flash Player for mobile devices to new browser, OS version or device configurations.

"Some of our source code licensees may opt to continue working on and releasing their own implementations. We will continue to support the current Android and PlayBook configurations with critical bug fixes and security updates."

The decision comes as Adobe plans to cut 750 staff, principally in North America and Europe. An Adobe spokesperson declined to give any figures for the extent of layoffs in the UK. The company reiterated its expectation that it will meet revenue targets for the fourth quarter.

The reversal by Adobe – and its decision to focus on the open HTML5 platform for mobile – brings to an end a long and tumultuous row between Apple and Adobe over the usefulness of Flash on the mobile platform. The iPhone launched in 2007 without Flash capability, as did the iPad in 2010.

Steve Jobs, then Apple's chief executive, and Apple's engineers insisted that Flash was a "battery hog" and introduced security and stability flaws; Adobe countered that it was broadly implemented in desktop PCs and used widely on the web.

Jobs's antagonism was partly driven, his biography reveals, by Adobe's reluctance after he rejoined Apple in 1996 to port its movie-editing programs to the Mac and to keep its Photoshop suite comparable on the Mac platform with the Windows one.

But Jobs also insisted that mobile Flash failed in the role of providing a good user experience, and also would restrict Apple's ability to push forward on the iOS platform. Studies of browser crash reports by Apple's teams showed that Flash was responsible for a signficant proportion of user problems; Apple was also not satisfied that a Flash plugin would be available for the first iPhone in 2007 which would not consume more battery power than would be acceptable.

Jobs managed to persuade Eric Schmidt, then Google's chief executive and a member of the Apple board, to get YouTube to make videos available in the H.264 format without a Flash "wrapper", as was then used for the desktop implementation.

But the disagreements between Apple and Adobe intensified, especially when Android devices began appearing which did use the Flash plugin. Apple refused to use it, and banned apps from its App Store which tried to use or include Flash.

In "Thoughts on Flash", an open letter published by Jobs in April 2010, he asserted that "Flash was created during the PC era – for PCs and mice. Flash is a successful business for Adobe, and we can understand why they want to push it beyond PCs. But the mobile era is about low power devices, touch interfaces and open web standards – all areas where Flash falls short.

"New open standards created in the mobile era, such as HTML5, will win on mobile devices (and PCs too). Perhaps Adobe should focus more on creating great HTML5 tools for the future, and less on criticizing Apple for leaving the past behind."

Adobe's chief executive Shantanu Narayen hit back at Jobs, saying that "Thoughts on Flash" contained statements about the plugin that were false (relating to battery drain).