X11

X11 for Mac

Upgrade OS to latest available (not always necessary, but usually avoids bugs)
Upgrade to (or install) XQuartz-2.8.5
Log out/Log in to your Mac (may not be needed for upgrades from earlier 2.8.0 releases)
starting Mac terminal (or x2go, if installed) should trigger xquartz.
For OpenGL graphics to work, you may need to turn on indirect GLX by typing the following into your terminal:
```
defaults write org.xquartz.X11 enable_iglx -bool true
```

If glxgears gives the error: “couldn’t get an RGB, Double-buffered visual”, add the following to your GreenPlanet .bash_profile or equivalent:
```
export __GLX_VENDOR_LIBRARY_NAME=mesa
```
If Matlab windows keep blanking out, create a file "java.opts" in your GreenPlanet home folder with the following content:
```
-Dsun.java2d.xrender=false
-Dsun.java2d.pmoffscreen=false
```
(If you start Matlab from a different folder, the java.opts may need to be put there instead.)

- Warning: Some ancient apps may require an even older version (2.7.8) of XQuartz due to incompatibilities with “El Capitan” and “Mojave”

Here are a list of X Windows servers for Windows

Requires an X2Go server on the target server. Creates a full remote desktop connection.

Note: X2Go is great for overcoming platform specific bugs like requiring certain versions of XQuartz for a given app on macOS

Terminal / SSH chient with X11 support.

https://mobaxterm.mobatek.net/download.html
https://mobaxterm.mobatek.net/download-home-edition.html (select Installer edition)

Note: works great for accessing CentOS/Ubuntu, but haven’t fully tested this personally to access X apps on macOS

Note: mileage varies depending on the repo (i.e., if it’s not up to date).

Requires an X2Go server running on the target server. Creates a full remote desktop session.

Client can be installed through the system repos, eg on Ubuntu:

sudo apt install x2goclient

As long as your current environment supports X11, X11 forwarding can be enabled for an SSH connection using the -Y flag, eg:

ssh -Y username@gplogin3.ps.uci.edu

The forwarding can be tested by running glxgears.