Immutable OSes are great, but not being able to --for instance-- install new distribution packages (or having to reboot every time you do so) may be really tedious, especially for developers. Except, you can install whatever you want without having to reboot, and without breaking the consistency and "the immutability" of the OS itself either. How? Well, in one word, with toolbox. In some more words: come to the talk. So, let's say that your driver is an immutable OS, like Fedora Silverblue, openSUSE MicroOS, EndlessOS, etc. And let's say you are a power user and/or a developer. So, how do you perform your daily tasks, and how do you do your development on such a system, where you cannot install the compiler for the language you're writing the code in? Why, you ask? Well, because immutable OSes are often cleaner, more consistent, more reliable, and a lot harder to break than traditional ones. But that comes at the price of (for instance, on Silverblue and MicroOS) having to reboot several times a day, which is often a showstopper. Unless we leverage containers in order to provide users with a read-write environment that can be easily spawned, and inside which they can "live" and do most of their work (especially if they're doing any development!). This is usually done with something called "toolbox". In fact, Fedora Silverblue has a toolbox. openSUSE MicroOS has a toolbox, which is similar but also different from Silverblue's one. But that's not all of it, e.g., someone came up with podbox and someone else with coretoolbox. This talk will show the reasons why having some kind of toolbox is absolutely necessary inside an immutable OS. We will also try to explain the differences between some of the existing approaches and their implementations. And, last but not least, we will showcase --through real-life examples-- how, by taking advantage of a toolbox, you can elect an immutable OS to be the daily driver of your main development workstation, and not have to reboot it (unless you actually want to!)