DeX is a feature on the Samsung Galaxy S, Galaxy Note, Galaxy Tab S series that differentiates Samsung’s flagship smartphones and tablets from the company’s competitors. DeX, which debuted back in 2017 with the Samsung Galaxy S8, lets users access a desktop mode UI, with support for Android apps, when connected to a monitor. Initially, DeX required a special accessory in the form of the DeX Station and later the DeX Pad, but with the launch of the Samsung Galaxy Note 9, Samsung made it work with any HDMI to USB Type-C cable, which means that it no longer required any specialized hardware. This significantly improved its versatility. The one real competitor to Dex is Huawei’s Easy Projection feature, which can also work wirelessly. However, Samsung still had a leg up over Huawei thanks to the Linux on DeX feature.

Linux on DeX enabled the user to get a full-fledged desktop GNU/Linux environment up and running on the smartphone in DeX mode. Specifically, Linux on DeX supported a modified version of Ubuntu 16.04 LTS for ARM64. Linux on DeX was first shown off all the way back at SDC 2017, and the company finally released a beta for download a year later. The feature was intended for developers and not for regular users, as only ARM64 packages could be used on Linux on DeX. It allowed developers to compile, build, and test Android apps on their smartphone itself. Max used Linux on DeX extensively on the Galaxy Note 9 and noted that it pushed the limits of the hardware at that time.

Linux on DeX was also supported on the Samsung Galaxy S10 series and the Galaxy Tab S5e, with its minimum requirements including a Qualcomm Snapdragon 835 SoC and 4GB of RAM. However, eleven months after its release, Samsung has abruptly killed off the beta for Linux on DeX.

The company has sent an email to participants in the Linux for DeX program, where it states that support for the program has ended with the Android 10 update (which is in beta form for the Galaxy S10, S10+, and the S10e). Samsung will no longer provide support on future OS and device releases. The company also notes that users will not be able to perform a version rollback to Android 9 Pie once they have upgraded to Android 10.

As of now, Linux on DeX still works on Android 9 on the devices where it is supported, but the feature is effectively dead for now. This is a pity as Samsung’s work here was unparalleled in terms of execution, even though it was relevant to only a small niche of users. While there are ways of getting a GNU/Linux environment running on any Android phone, none of these ways are as polished or as feature-rich as Linux on DeX. The company has not provided the reasons for killing the feature, but the most likely one is that it saw very little use from a small subset of the market that purchases Samsung’s devices. The ARM64-only packages installation limitation ensured that Linux on DeX was not as versatile as the regular DeX mode.

Android 9 users on supported devices can still try Linux on DeX for now by downloading the APK from APKMirror and the system image from Samsung’s website.

Thanks to XDA Member @mautz001 for the tip!