It’s been a busy morning for Microsoft. The company today announced the wide availability of Windows 8.1 and Visual Studio 2013, along with opening the Windows Store to developer app submissions.

Microsoft also released a blog post with advice for developers on how to proceed with creating apps using the official versions of VS 2013 and Windows 8.1. App packages that worked on preview versions need to be updated or they won’t be accepted into the store, and apps written in JavaScript and HTML come with special update instructions.

(More on Windows 8: Making a better user experience for Windows 8)

Developers with Windows 8 apps can follow instructions to retarget their apps, importing their projects into Visual Studio 2013 to integrate capabilities for new 8.1 features. Windows 8.1 includes a slew of new APIs and developer features, such as new app bundles, a scheduler API, HTML and JavaScript controls with custom commands, and enhanced navigation support. There are also updates and added capabilities in DirectX programming, file management, networking, multimedia, security, design tools, and the UX/UI.

Windows 8.1 and Visual Studio 2013 are both available for download now.