X2Go Ephyr

X2Go Ephyr is a new kdrive X Server for X2Go. It could be used instead of x2goagent. X2Go Ephyr works similar to Xephyr and based on it's code. It won't replace x2goagent, users will be able to chose if they want to run their sessions in x2goagent or in X2Go Ephyr.

The main reason - we want to be able to run modern desktops such as Unity, KDE-5, Gnome-3 and the applications built with the latest toolkits without limitations.

x2goagent (or nxagent) is based on NX technologies. It's basically kind of X-proxy. It accepting X-protocol requests from X-Client and forwarding them to remote X-Server. In opposite, X2Go Ephyr is a real X-Server. It's processing the requests from X-Client and rendering images on the remote display, like normal X-Server rendering them into the graphic display, using the video driver. You could say, that the difference between x2goagent and X2Go Ephyr it's the same as difference between Xnest and Xephyr.

NX-Protocol using the network transparency of X-protocol. It mean's that instead of sending images over network, it sending the X-requests like “create window” or “move window from one position to another” or “write text in the window”. So if you running legacy X-applications, it'll work much faster on the slow networks, than protocols, which are transferring images between server and client.

Unlike the NX-libraries, which are based on obsolete X.Org-6, X2Go Ephyr is based on the recent X.Org-7. It brings multiply advantages:

• We can run without any limitations any modern Desktops and applications.
• We don't need to support obsolete X code, which makes the development and support much easier.

If x2goagent is just a proxy between X-Servers on the server and client sides, X2Go Ephyr is a standalone X-Server. It brings a lot of advantages over NX-protocol:

• We don't need an X-Server on the client side. This is a main advantage. If we want to use NX-Libraries, we always need a fully functional X-Server on client, like XQuartz on Mac or VCXsrv on Windows. X-applications are not native to this OS and are always the source of many troubles. Another OS, like Android or IOS, doesn't have any usable X-Server software at all. Using X2Go Ephyr we can avoid this issue and build native clients for any platform and even develop HTML5 client.
• The X2Go Ephyr architecture is better suited for the modern application like Firefox or Chromium. This applications are developed to run on different platforms and using cross-platform graphic libraries like Skia. Modern browsers and some other applications working much better with X2Go Ephyr than with NX.

X2Go Ephyr works similar to Xephyr with only difference, that it's not rendering frames in the X-window but transferring them instead over the network to xephyrclient. Xephyrclient running on the client computer, rendering the frames, capturing the input events and sending them back to the server.

xephyrclient and x2goephyr binaries are made to be compatible with nxproxy and x2goagent. You can just rename xephyrclient to nxproxy and x2goephyr to x2goagent and start the X2Go session using X2Go Client. It works only if X2Go Client is running on Linux. The versions of X2Go Client and X2Go Server, which can run parallel x2goagent and X2Go Ephyr sessions are coming soon.

Please keep in mind:

• This is not a stable software.
• Use it on your own risk and don't use it in productive environment.
• At the moment it's only a preview version. We assume you know how X2Go works and you know what are you doing.

We don't have a binary builds yet. If you want to try it, you need to build it by yourself or wait until binary packages are ready.

Or just take a look at screenshots:

KDE-5 on Open SUSE Leap 42.3

xephyrclient display menu

Gnome-3 in SLE-classic mode on SLES 12sp1

Gnome-3 in modern look on Debian Stretch.

download the x2goephyr from git:

x2goephyr

We assuming, that you are familiar with make, Xorg and know how to build software from sources.

You'll need a xorg-server sources (1.19.2), zlib, libpng and libjpeg.

Configure Xorg to build xephyr and start a build process (make). After that copy x2goephyr directories in xorg-server/hw/kdrive, than change to xorg-server/hw/kdrive/x2goephyr and run make x2go. This should build x2goephyr binary.

The simplest way to build x2goephyr if you are using your system source packages. I'll give some examples for Debian, SLE12sp1 and OpenSUSE Leap 42.3

• Install apt-source, and get source for xorg-server apt-build source xorg-server
• Go to the source directory and build it with dpkg-buildpackage
• Copy x2goephyr sources to xorg-server-1.19.2/hw/kdrive/
• Create directory 'x2goephyr' in xorg-server-1.19.2/debian/build/main/hw/kdrive/
• Link Makefile from xorg-server-1.19.2/hw/kdrive/x2goephyr to xorg-server-1.19.2/debian/build/main/hw/kdrive/x2goephyr
• Go to xorg-server-1.19.2/debian/build/main/hw/kdrive/x2goephyr and run make x2go

• Download xorg-server SRPM for your system and install it
• Install all dependencies you need to build xorg-server
• Build xorg-server from SPEC file
• Copy x2goephyr sources to BUILD/xorg-server-<your version>/hw/kdrive
• You'll need apply a patch for your system: patch -p1 < osuse_42.3.patch or patch -p1 < sles12sp1.patch
• Build binary: make x2go

To build xephyrclient you'll need QT-5.

• Get it from git: xephyrclient
• Build it like any qt project: qmake && make

• Works with recent desktops and software
• Supports SW 3D acceleration
• Supports RANDR, works with multiply desktops in window and full screen modes
• Supports JPEG and PNG compression
• Supports frame caching
• Can recognize windows scrolling and doesn't transfer frame areas, which are already in cache.
• Works with 3D acceleration (if you are using Virtual GL)
• Has QT client for Linux and Windows (Mac client not ready yet, but it's not complicated, only keyboard encoding is missing)

• Proper build scripts and integration with jenkins
• Support in X2Go Client and X2Go Server (it's actually done, just need to discus how we'll integrate it in our builds)
• Clipboard support
• Mac client
• Different optimizations for slow networks, frame dropping, etc
• Video encodings
• HTML5 client
• ….