Build, Microsoft’s annual conference for independent, third-party developers, is taking place through April 2 to April 4 at the Moscone Center in San Francisco. The Build Developer Conference is an annual event sponsored by Microsoft aimed at developers working on the Windows Phone platform, Microsoft Windows Azure apart from other Microsoft platforms and technologies.

But why Build is so important this year? One thing unveiled at this year’s Build 2014 is an update to Windows Phone 8.1, with details on the new features in the operating system and possibly a launch date. Not only did the company put updates to the mobile operating system on display, Microsoft also discussed the new model that will help developers build applications and games compatible with Windows Phone, Windows RT/8 and other Microsoft products.

While the Day 1 keynote at Build focused more on consumer products including Windows and Windows Phone, Day 2 keynote focused mainly on developers’ tools. This year’s big push in the Build 2014 developer arena is in cross-platform apps.

Universal cross platform apps

At this year’s Build, Microsoft has decided to give Xbox One and Microsoft Store credit in the form of a $500 gift card to developers. With these, developers will be well on their way to creating cross-platform, universal apps.

Microsoft’s focus on cross-platform apps is seen as a strategy by the service company to lure developers to create universal apps not only for Windows, but for Windows Phone and Xbox One. App frameworks previously focused on Windows desktops, Windows Phone and Windows Surface have been unified from a development perspective.

“With the Windows Phone 8.1 release, we brought the new Windows Runtime to phones. Now you can produce common apps across phones, PCs and tablets,” said David Treadwell, corporate vice president at Microsoft. “To enable universal Windows apps, we’ve streamlined every phase of the windows development.

“You need to reach customers across multiple devices. Windows will help you do that. We know you’ve made a huge investment in your code and you need to carry that forward. Windows will help you do that. You need to be able to deliver apps across platforms. Windows will do that.”

Microsoft also showcased an open sourced WinJS across multiple platforms including iOS and Android, introduced new SDKs for imaging and motion sensing from Nokia, and pushed down the cost of low-end Windows tablets by making the OS free to OEMs for embedded IoT devices and sub-9″ screens.

With all these latest releases, Windows Phone and Windows development now have common APIs, making it possible to build apps that run on both platforms. Microsoft said 90 percent of APIs are now common across Windows, Windows Phone, and Xbox.

Microsoft demonstrated a new touch-first version of Office that’s built using the new Universal features. The new app will work not only on the big size Surface tablet but also that Windows Phone gets the same features, just with a user interface that’s more suitable for smaller screens.

Developers can use a single project for all versions of an app and can build one app that has the same app identity in the different Microsoft stores. Microsoft will give developers tools to tune which users get which rights, with the aim of giving them as many monetization options as possible.

Microsoft open source approach extended to JavaScript

Microsoft is open sourcing its WinJS user interface library to get the benefits of Microsoft’s new developer tools. The Windows Library for JavaScript is a cross platform tool that will run on any device. Developers can build apps using Apache Cordova for use in iOS and Android apps.

WinJS is a JavaScript library that was first created for Windows 8 to enable first class, native-quality experiences in Windows Runtime apps using familiar web technologies like HTML, CSS, and JavaScript. According to Microsoft, WinJS is now available for building apps across Microsoft platforms and devices, it is ready to extend to web apps and sites on other browsers and devices including Chrome, Firefox, iOS, and Android. Extending WinJS to other browsers and devices beyond Windows further extends their reach and allows them to bring the personality of Windows apps to the web without rewriting code or learning new skills.

Azure Preview Portal

Microsoft announced a new Azure portal that brings together cross-platform technologies, services and tools for developers. With the new portal, Microsoft is intent on delivering a fantastic cloud platform as well as a great platform for developers to be able to build applications and services and deploy them.

The advantages of the new Microsoft Azure Preview Portal are that Microsoft provides an end-to-end application lifecycle management solution, starting from an idea to writing a service to debugging and deployment.