Unable to contain itself, Microsoft released a new Windows 10 build today, bringing bug fixes, user interface improvements and new Mail and Calendar applications.

In the new build, Microsoft added a new ‘black system theme’ for a number of core user interface elements, including the Start Menu and Taskbar. The company also revamped Windows 10’s tablet mode, officially called Continuum, to make it easier to select common buttons by making them, well, larger.

Microsoft’s effort to create one operating system that can run across any device form factor depends on that sort of work working. If you’re a regular Surface user, you’re probably already pretty familiar with the bump that goes along with shifting from tablet mode to a desktop experience and back. There is still some time left for Microsoft to sort the flip

As with all Windows 10 builds, there are bug fixes — I quote to preserve tone: “Visual Studio will no longer crash when creating a new Universal app project” — and new bugs. For example: “Downloading music in the Xbox Music and Music Preview apps is currently broken.” The full list is here.

Microsoft also released a new Windows 10 for phones build yesterday. It almost feels that the company is accelerating the pace of its build cycles. Which is odd given that Build, Microsoft’s yearly developer confab, is next week. I presume the company has goodies in store.