https://support.apple.com/en-us/HT201341
http://www.xquartz.org/
http://www.x.org/wiki/
learn to use it:
http://www.linuxjournal.com/article/4879
Check out this video tutorial
http://en.tldp.org/HOWTO/XDMCP-HOWTO/index.html
+++++++++++++++++++
did this to fix login problem on kubuntu box...
http://ubuntuforums.org/showthread.php?t=1334632
I loaded x11vnc on the kubuntu box
http://askubuntu.com/questions/229989/how-to-setup-x11vnc-to-access-with-graphical-login-screen
I was getting x11 authentication erors even though ssh logged in with public and secret keys.
This solved the problem:
http://askubuntu.com/questions/377053/x11-ssh-issues-wrong-authentication
.Xauthority had to be owned by chad and chad group, not root
======================
loginto kubuntu:
ssh -Xv chad@192.168.1.25
result of verbose:
OpenSSH_6.9p1, LibreSSL 2.1.8
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 20: Applying options for *
debug1: /etc/ssh/ssh_config line 102: Applying options for *
debug1: Connecting to 192.168.1.25 [192.168.1.25] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_rsa-cert type -1
debug1: identity file /Users/MAC_at_home/.ssh/id_dsa type 2
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/MAC_at_home/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.9
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.6
debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.6 pat OpenSSH_6.6.1* compat 0x04000000
debug1: Authenticating to 192.168.1.25:22 as 'chad'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client chacha20-poly1305@openssh.com <implicit> none
debug1: kex: client->server chacha20-poly1305@openssh.com <implicit> none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:zfXl/BD3s9Suz6kSOpSyU6BlPP89FSbPUgDdg3Tcrbs
debug1: Host '192.168.1.25' is known and matches the ECDSA host key.
debug1: Found key in /Users/MAC_at_home/.ssh/known_hosts:2
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering DSA public key: /Users/MAC_at_home/.ssh/id_dsa
debug1: Server accepts key: pkalg ssh-dss blen 433
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.1.25 ([192.168.1.25]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: Sending environment.
Welcome to Ubuntu 14.04.4 LTS (GNU/Linux 3.16.0-62-generic x86_64)
* Documentation: https://help.ubuntu.com/
Last login: Tue Mar 15 19:15:18 2016 from 192.168.1.11
chad@chad-System-Product-Name:~$
======================================
one can run firefox on kubuntu and display it on the MAC:
chad@chad-System-Product-Name:~$ firefox
debug1: client_input_channel_open: ctype x11 rchan 3 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54630
debug1: channel 1: new [x11]
debug1: confirm x11
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54631
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: client_input_channel_open: ctype x11 rchan 5 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54632
debug1: channel 3: new [x11]
debug1: confirm x11
debug1: channel 3: FORCE input drain
debug1: channel 3: free: x11, nchannels 4
debug1: channel 2: FORCE input drain
debug1: channel 2: free: x11, nchannels 3
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54633
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: channel 2: FORCE input drain
debug1: channel 2: free: x11, nchannels 3
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54634
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: channel 2: FORCE input drain
(firefox:4225): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-pYVRNvcfmV: Connection refused
debug1: channel 2: free: x11, nchannels 3
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54635
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: channel 2: FORCE input drain
debug1: channel 2: free: x11, nchannels 3
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54636
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: channel 2: FORCE input drain
debug1: channel 2: free: x11, nchannels 3
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54637
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: channel 2: FORCE input drain
(firefox:4225): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-pBD6yINuxE: Connection refused
debug1: channel 2: free: x11, nchannels 3
(firefox:4225): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Could not connect: Connection refused
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54638
debug1: channel 2: new [x11]
debug1: confirm x11
debug1: client_input_channel_open: ctype x11 rchan 5 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 54641
debug1: channel 3: new [x11]
debug1: confirm x11
debug1: channel 3: FORCE input drain