Ionic is the company behind a trendy eponymous open-source HTML5 framework and software development kit (SDK) for building native mobile apps and mobile web apps. Today, it’s announcing an $8.5 million round of funding.

Ionic has landed the new funds at a time when big technology companies are doubling down on tools to more effortlessly develop mobile-friendly applications. In February, Microsoft acquired Xamarin, a company with tools for taking C# code and building mobile applications with it. (Xamarin’s SDKs are now available under an open-source license, and Microsoft has previously open-sourced the .NET framework.) Before that, Microsoft talked up the value of open-source Apache Cordova. Apple, for its part, has the open-source Swift programming language as a successor to Objective-C. Facebook has React Native. But these tools only get you so far in the eyes of Ionic cofounder and CEO Max Lynch.

Not every developer is hip to Swift or Objective-C, Lynch said. Xamarin is limited to C# and the .NET framework, he explained, while React Native is only meant for apps that go to the app stores. And Cordova, well, it “provided part of the equation, it helped get web content in a native app shell, but it didn’t help with the UI [user interface],” Lynch told VentureBeat in an interview.

Ionic, which is based on the AngularJS JavaScript framework and supports CSS alongside HTML5, has taken off in open-source software land. As of this moment, it has 23,536 GitHub stars. Lynch said millions of developers are using Ionic, with “a couple hundred thousand” SDK downloads every month. More than 2 million applications have been build with Ionic, he added.

But now, of course, the push is to get enterprises to pay. So there will be more salespeople coming on board. And there will be more commercial services coming — things like the Ionic Insights analytics tool and some kind of add-on functionality that allows developers to easily begin consuming other services once they’ve started using Ionic.

Competitors include Sencha and Appcelerator. Ionic focuses on making its primary tools freely available under an open-source license.

General Catalyst led the round. To date, Ionic has raised $12.2 million.

Ionic started in 2011 and is based in Madison, Wisconsin. The company currently has 20 employees, and the headcount could reach 25-30 within a year, according to Lynch.