At Black Hat USA 2015, Kali 2.0 was released with a new 4.0 kernel. It is based on Debian Jessie, and it was codenamed as Kali Sana. The previous major release of Kali was version 1.0 with periodic updates released up to version 1.1. Cosmetic interface changes for better accessibility and the addition of newer and more stable tools are a few of the changes in Kali 2.0.

Some major improvements in Kali 2.0 are listed here:

• Continuous rolling updates: In January 2016, the update cycle of Kali Linux was improved with the shift to a rolling release, with a major upgrade in April 2017. A rolling release distribution is one that is constantly updated so that users can be given the latest updates and packages when they are available. Now users won't have to wait for a major release to get bug fixes. In Kali 2.0, packages are regularly pulled from the Debian testing distribution as they are released. This helps keep the core OS of Kali updated.
• Frequent tool updates: Offensive Security, the organization that maintains the Kali Linux distribution, has devised a different method to check for updated tools. They now use a new upstream version checking the system that sends periodic updates when newer versions of tools are released. With this method, tools in Kali Linux are updated as soon as the developer releases them.
• A revamped desktop environment: Kali Linux now supports a full GNOME 3 session. GNOME 3 is one of the most widely used desktop environments, and it is a favorite for developers. The minimum RAM required for running a full GNOME3 session is 768 MB. Although this is not an issue, considering the hardware standards of computers today; if you have an older machine, you can download the lighter version of Kali Linux that uses the Xfce desktop environment with a smaller set of useful tools. Kali Linux also natively supports other desktop environments such as KDE, MATE, E17, i3wm, and LXDE. Kali 2.0 comes with new wallpapers, a customizable sidebar, an improved menu layout, and many more visual tweaks.
• Support for various hardware platforms: Kali Linux is now available for all major releases of Google Chromebooks and Raspberry Pi. NetHunter, the hacking distribution designed for mobile devices, which is built upon Kali Linux, has been updated to Kali 2.0. The official VMware and VirtualBox images have also been updated.
• Major tool changes: The Metasploit Community and Pro packages have been removed from Kali 2.0. If you require these versions, you need to download it directly from Rapid7's website (https://www.rapid7.com/). Now, only Metasploit Framework—the open source version—comes with Kali Linux.