Build 2016: Weeks after purchasing Xamarin, Microsoft makes it free for everyone - and open source, too

Scott Guthrie explains Microsoft's strategy for Xamarin

Microsoft this week threw in a big surprise at its Build 2016 developer conference with the announcement that it would make its C#-based mobile development platform Xamarin free - just weeks after purchasing the San Francisco, California-based start-up.

Microsoft's purchase of Xamarin seemed to make business sense for a company that's had to give up on in-house attempts to port Android apps to the Universal Apps platform. But the biggest question was always going to be the cost to developers to keep using Xamarin.

It was left to Scott Guthrie, product manager of .NET at Microsoft, to explain the company's strategy.

"It's great to have [Xamarin co-founder] Miguel [de Icaza] and his whole team as part of Microsoft and the .NET framework. But I've been asked a lot since we announced our intention to acquire Xamarin: what is the pricing for Xamarin going to look like now it's part of Microsoft?" he said.

"We officially closed the Xamarin acquisition about 10 days ago, so we can now officially share plans. Starting today, I can officially announce we're going to be making Xamarin available at no extra charge."

Applause was thunderous and absolutely genuine (unlike throughout most of yesterday's Build 2016 keynote as professional salaried superfans hollered and whooped at the merest mention of an announcement).

Guthrie went on to explain that this "no extra charge" applies to Visual Studio Enterprise and Professional Editions and, better yet, the freebie Visual Studio Community Edition.

He also revealed that Xamarin is being launched in a special free version on the Mac, entitled Xamarin Studio Community Edition.

And the crowning glory? "Like we've already done with ASP, .NET, Entity Framework, C# and Rosyln, and the core .NET runtime, we'll also make Xamarin's core platform open source and contribute it as part of the .NET Foundation," said Guthrie.

There wasn't a dry eye in the house, especially as Guthrie added that 3D games development platform Unity, intelligent development toolset JetBrains and stalwart Linux botherer Red Hat have also joined the .NET Foundation.

It's important to note that Microsoft isn't just giving away the Xamarin source code wholesale. Co-founder Nat Friedman said on Hacker News after the keynote that only runtime and command line tools needed to build apps are being released.

But overall, it seems reasonable to believe that Microsoft is not going to do something awful to Xamarin, and we can all go about our business. At least for now.