KiCAD 7.0.0 released.

[SiliconWizard]

You can make them coexist. They can't share libraries as v7 libraries are not compatible with v6. You can reuse your v6 libraries in v7, but not the other way around - thus keeping separate libraries is the only safe way of using both versions.

On Windows, it's mainly a matter of installing v7 in a different directory. On Linux, well. Depends. See with your distro how to handle this. On most distros, the kicad package has now been updated to v7 and will just update your v6 install - having both coexist is usually a bit trickier on Linux.

In any case, again be careful with your custom libraries. As soon as you'll change anything in your libraries from v7, they will become unusable in v6. Keeping a separate copy of your custom libraries is a much safer bet, although obviously it can get pretty inconvenient.

[JohanH]

having both coexist is usually a bit trickier on Linux.

One option is to install v6 from the repository (apt, dnf etc.) if it's still offered by the distribution and v7 as a flatpak. The situation is not stable, as the distribution could update the repository version at some point. It's also possible to have custom installed flatpaks, meaning that they are installed in a custom location. This way it could be possible to have multiple versions, but it's a bit messy. The most stable way I can think of is having multiple virtual machines, which is no big deal in a linux system (I'm using Gnome Boxes for virtual machines on my desktop).

[SiliconWizard]

Yeah, flatpaks.

Otherwise, if you know how to compile it (it's not that hard), you can compile it yourself and install it wherever you want.
For instance, before v7 got released on Arch, I compiled it myself and installed it in /opt/kicad/kicad7.

If you can compile software from source, this is the way to go if you don't want to rely on flatpak stuff. Of course, in this case, it's absolutely not managed by any package manager so you're on your own to update it.

[SiliconWizard]

7.0.1 is released.