Tomek Kondrat of XDA Developers said it in the best way I think it will ever be said; "It's hard to imagine the XDA world without the Xposed Framework." Indeed, Xposed Framework has provided an insane amount of tweaking and customization to even stock phones, so long as they can be rooted and have their system files messed around with just a bit. Nowhere is this more evident than in the Samsung world. Samsung's TouchWiz is an extremely unique software that some users may love, others may hate and still others may only want some part of. You may also own a fairly recent Samsung device, such as the Galaxy S6, for whom the custom ROM scene is still in its infancy. Shoddy rebrands and slight tweaks, known as "kangs", of a half-broken Cyanogenmod show up fairly often for the young handset, leaving a great number of users cold. For those who take part in Samsung's beta software tests and have moved on to Marshmallow, you'll no longer have to miss Xposed Framework.
Posted up by community cornerstone Wanam to the Galaxy S6 forum, this newest incarnation of the famous Xposed Framework comes with some fairly complicated installation instructions. Although straightforward, these instructions involve modifying the phone's bootloader multiple times using Odin, Samsung's proprietary flashing tool. An open-source alternative is available, known as Heimdall, but the process is basically the same. It should go without saying that your warranty will be voided, Knox will be tripped and you'll have some serious issues getting Samsung Pay to work, if you can at all. For some, however, the customization and system tweaking capability that Xposed offers is well worth it.
Samsung's approach to Android software development gives developers more than a few headaches with the myriad security patches, proprietary software and Samsung's unique fork of ART, the backend of Android known as the Android Runtime. That makes it an especially huge achievement to see something as system-heavy as Xposed this early on, especially for an update that's still in beta. According to Wanam, this is only possible because Samsung decided to leave the meddling to a minimum for this update. In his words, "Samsung did it in clean way this time, just a small changes to Art plus the Konx security ones of course."