Linux

Just the old .ssh/config file, works like a charm on all terminals :)

Konsole has an SSH Manager plugin you can enable.

ssh.serverdomain scripts that immediately can do things like turn on the required vpn. In combo with SSH keys and non port 22, it's ideal

I hear ya on RDP. Sadly I still need to use that at times so reminna is good.

Otherwise, I just use tmux. Colleagues use https://midnight-commander.org/ for SCP and stuff of you like. I prefer simple rsync and whatever but they seem to like it. Something to look into.

Konsole (KDE's Terminal) has built-in SSH management features:

https://www.techrepublic.com/article/use-kde-plasmas-konsole-ssh-plugin/

I just use ~/.ssh/config

e.g.

Host website
    Hostname some.hostname.foo
    User bob
    Port 1500

in my terminal I press ctrl + r and then type the name of the machine

Not a GUI, but I keep my ~/.ssh/config clean by splitting my configs into folders, and including them in the main ~/.ssh/config.

I have the folder, ~/.ssh/config.d/, and here's what it looks like:

~/.ssh/config.d
.
├── work
│   ├── dev.config
│   ├── staging.config
│   └── prod.config
└── server
    ├── development.config
    ├── containers.config
    ├── home.config
    ├── pis.config
    └── server.config

Then my ~/.ssh/config looks like this:

Include config.d/work/*
Include config.d/server/*
Include config.d/other/*

The reason you are having trouble finding a replacement is because thats not really how the linux world approaches things.

Learn the terminal, scp, ssh (esp key auth if you havent), sshfs, tmux, vim or emacs and you will find you are incredibly effective at modern admin tasks. If you havent already, look into something like saltstack or ansible to make your life even easier.

ssh config? Not sure what you're looking for. Like a list of preconfigured connections?

How about XPipe?

https://xpipe.io/

It can even auto-configure itself by parsing out your ~/.ssh/config so you can keep everything defined there for easy CLI access but also use the GUI when desired.

XPipe is what I use, supports syncing via git, SSH, sftp, RDP, vnc, etc.. And can manage docker containers too. It also has scripts you can define that automatically work on any SSH connection.

Uh, I just type ssh or rsync into the terminal and that's it. It's a manageable amount of computers/servers I connect to, so I can remeber their names. Regular ssh stores all the keys or custom ports / IPs in its config. What's the advantage of using some manager?

I really like Asbru and have been using it for a couple of years. I used Remmina for a little while but never liked its look and feel.

Not too much active development has been going on lately, sadly, but the latest version still works very well.

https://www.asbru-cm.net/

Take a look at PortX. Just installed it today in Windows and Fedora 42. I have a Synchthing server where I store a Veracrypt vault with the public keys.

Remmina is great but no Windows option.

Use Tabby. It is, by far, the closest to a Linux terminal experience. Likely because it's cross platform. I say this as someone that absolutely despises Windows terminal experiences.

I just install my keys as needed to the machines and then configure aliases for quick connections. For file transfer with SFTP I'm using Filezilla because its queuing functionality and site management are nice.

I think for what you are looking for, both puTTY and Remmina should be capable as well as the other options suggested here

I'll be watching this discussion, as I'm currently using Remmina. It meet the bare minimum of SSH & RDP, but it doesn't have a clear method to organize connections and instead uses a big list. I also find the interface a tad counterintuitive, so maybe I'm just using it wrong.

It also seems to have a bug where it launches twice whenever I start my computer. So I have to close one.

Muon.

Does SSH, SFTP and other stuff.

I would say, like many others, Remmina.

Putty also has a Linux version, so you can use that as well. Its session management is a bit clunky, but it works and it offers some fairly good functionalities.

But ssh is first and foremost a command line tool. As others have said, invest some time to learn its commands and configuration files.