Microsoft has released a new version of the Windows 10 Preview, build 10061, to members of the Insider program for beta testing and feedback. Compared to the previous Preview build, this new build features a number of general improvements, additions and fixes across the board.

The biggest addition to Windows 10 in this build are updated Mail and Calendar apps, which bring improved performance, more streamlined interfaces, and new features. The Mail app in particular has received a ton of new stuff, such as swipe gestures for flagging and deleting emails, and a revamped authoring experience that "leverages the familiar and rich capability of Word".

Microsoft has also improved Continuum, which is Windows 10's way of modifying system behavior depending on whether a device is being used in a tablet mode with a touchscreen, or in a laptop/desktop mode with a keyboard and mouse. In the latest build of Windows, Microsoft has tweaked Continuum to make certain UI elements more touchable when in tablet mode.

There are several new theming features in the latest Windows 10 build, including a black system theme, transparency for the Start menu and Taskbar, the ability to resize the Start menu, and new coloring options. On top of this, Microsoft has made some minor visual changes to Task View, and improved the Virtual Desktop experience.

Windows Insiders in the Fast ring can now download build 10061 through Windows Update. Expect to hear more updates about Windows 10 this time next week as Microsoft's Build 2015 conference kicks off in San Francisco.