Washington, United States — Microsoft CEO Steve Ballmer pumped up unique features in the company’s new Web browser and smart phone software at a software developer conference Thursday, the company’s annual pep rally for people who will build programs for the Web, Windows computers and phones.

Ballmer is known for his onstage enthusiasm. This year, he joked with the crowd that he wouldn’t repeat the memorable “developer prance” of years past, when he loped around hollering, “Developers! Developers!”

Dean Hachamovitch, a top executive in Microsoft Corp’s Internet Explorer division, showed off how developers can program websites to take advantage of new features. Internet Explorer 9, which is in beta test form, uses more of a PC’s hardware to make pages load and run faster. A new version of the underlying code is being released for developers Thursday.

IE9, which is only available for computers running Windows Vista and Windows 7, lets computer users “pin” websites to the task bar at the bottom of the screen, creating a permanent shortcut that makes the site feel more like a desktop program.

Microsoft also unveiled some new apps — add-on programs that can be downloaded — for Windows Phone 7, its new smart phone software. One was a version of Amazon.com Inc.’s Kindle e-book reader software. Microsoft’s app marketplace now has 1,000 approved programs and games; the first Windows Phone 7 devices go on sale in the US in early November.

Most of the keynote presentations centered on what software programmers can build with Microsoft’s tools. Microsoft is far behind Apple Inc. with its iPhone and Google Inc. with its Android smart phone software; tens of thousands of apps are already available for those phones and have been critical to their success.

But one of Microsoft’s greatest strengths is its relationship with developers. The company’s tools, which it is updating, will be familiar for developers who already make programs for Windows PCs, and Microsoft is hoping that will encourage them to build apps even though the popularity of the phone is unproven.

“We need your best work,” Ballmer said to developers. “Make no mistake about it, when it comes to Windows Phone, we’re all in.”

Ballmer said Microsoft will give all developers who attend the conference at its Redmond, Washington, headquarters a Windows Phone 7 smart phone — more than a week before it goes on sale.

Microsoft also updated developers on its Azure system, which it describes as an operating system for “the cloud” — in other words, technology that allows programs to run not on a single computer or server, but across thousands of machines in data centers scattered around the world.

Walt Disney Co’s Pixar Animation Studios demonstrated a real-world example of how Azure works. The maker of the “Toy Story” movies is also responsible for the visual-effects rendering software used by many other movie studios. Rendering effects is computing-power intensive, and in the past it required studios to invest in massive data centers to crunch files.

Pixar built a version of the rendering software so it runs on Azure. It lets movie studios upload their raw files to the cloud. The studio can decide how fast it wants the computing done, and the service ramps up the right number of machines to complete the work. The studio pays based on how much computing resources it uses, but doesn’t have to buy a huge server farm.