Hello, I’m new here but am a long-time Linux Mint MATE user, going back to 2013 
I’ve installed Ubuntu MATE and am wondering how I can find a GUI tool to install software? I understand the Software Boutique is deprecated, but I can’t find anything in the menus (I’m using the “traditional” layout, with Applications/Places/System) that can be used for installing software.
Thank you for your help.
You can install FlatPak.
Providing your release can be helpful, at a minimum it allows me or others to respond with links that perfectly match your unstated system, so I'll use the latest release for links here (ie. Ubuntu MATE 25.10).
Included on the ISO or by default for that release is the snap store, ie. in the manifest file is
snap:snap-store 2/stable/ubuntu-25.10 1300
The deb equivalent is probably gnome-software, though in many ways the default snap store maybe better suited for Ubuntu [MATE] than upstream's GNOME Software; but you decide. Extensions can be added to make it more useful; but that's already done for you with the snap store.
A favorite package manager is Synaptic, and whilst the Package Manager is a different thing and is limited to deb packages only; it's actually very useful.
I hope these maybe useful to you, but I'd take advice from others (esp. in regards for usefulness/best) that actually use them, as I use none of them myself sorry.
Hi, @wherahiko and welcome to the Ubuntu MATE Community!
I agree with you, Synaptic is my go to software installer. If it's not in Synaptic but a .deb file I use gdebi. I do not use snaps or flatpaks except snaps that are par of the system. I will use appimages if there is no other alternative. I do have a web browser (Waterfox) installed from a tar file also.
I personally use Synaptic for the vast majority of my software installs.Gdebi for those few apps that are standalone downloads.
Realistically if you're looking for an "all in one" gui app for software I'd go with gnome-software with both the Flatpak and Snap plug-ins.
wherahiko
If you go: Applications > System Tools > Snap Store
You should find what you need
W
Ah, apologies. I’m using 25.10. But I installed the ARM version of Ubuntu Server 25.10 and then installed ubuntu-mate-desktop on top of it. (That seemed the only way to get an ARM version to run in a VM on a Silicon Mac.)
I’m guessing that’s why my install didn’t have the snap store. I wonder what else is missing, then?
I have installed Synaptic from the command line now.
Thank you, everyone, for your answers!