Microsoft CEO Satya Nadella during the Build conference keynote Wednesday. Photo courtesy Microsoft.

Microsoft CEO Satya Nadella during the Build conference keynote Wednesday. Photo courtesy Microsoft.

Microsoft kicked off its Build developer conference in San Francisco today, and the message was clear — developers won’t have to build applications exclusively for Windows, and those applications will work on multiple devices. Here were the highlights:

Android, iOS, code can be repurposed for Windows

There aren’t many custom apps built for the seldom-used Windows Phone operating system, so Microsoft is making it easier for developers to take existing code that work on Android and iOS devices and tweak it for Windows phones.

Developers have traditionally had to rework entire apps to function on Windows, which resulted in a meager Windows app marketplace compared with the robust offerings on Android and iOS devices. To encourage developers to consider Windows, the new Universal Windows Platform will feature toolkits that allow iOS- and Android-enabled code be tweaked, not rewritten, to work on phones running Windows 10.

“The theme is to start with your existing code base, and then extend,” Windows chief Terry Myerson said at the conference. “We want to embrace devs where they are.”

Apps will work on all Windows 10 devices

Windows leader Terry Myerson. Photo courtesy Microsoft.

Windows leader Terry Myerson. Photo courtesy Microsoft.

Microsoft clarified which apps will be able to run on its HoloLens hologram device — all universal Windows 10 apps. The conference featured a demo of HoloLens, in which the tester had app holograms hanging (floating? stuck to? materializing?) on the wall. He chatted on Skype, watched a video, and surfed Microsoft’s new web browser, moving and resizing everything around the room. Active applications, with the voice command “follow me,” will follow the user around the space.

Myerson reiterated that universal apps will be a cornerstone of Windows 10, with HoloLens being in the device ecosystem.

And speaking of that new broswer …

‘Project Spartan’ is now Edge

We’ve known since January Microsoft was planning to faze out Internet Explorer with a new browser that was called ‘Project Spartan’ in Redmond. Well, Spartan is officially called Edge, and it will be a streamlined cousin of Explorer. Tabs are better integrated a la Google Chrome and Mozilla Firefox, the virtual assistant Cortana is built in, and the browser allows for annotations with a stylus.