KDE 3.1: Desktop Sharing in Practice

Desktop Sharing is a KDE service that allows you to share your desktop using the RFB protocol, better known as VNC. This new feature of KDE 3.1 allows a friend or administrator to fix problems on your computer, or you can use it to show your desktop to somebody else at a remote location. It is compatible with all regular VNC / RFB clients.

Tim Jansen has created an overview page where he explains how to set up the Desktop Sharing, together with a nice interactive demo.

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by Tim Jansen (not verified)

As you can easily see, Desktop Sharing needs better icons. Feel free to create them :)
(developers who implement the stuff on the TODO list wouldn't hurt either :)

by not me (not verified)

Thanks for the pointer to the "uninvited connections" checkbox. I missed it before when I was looking for a way to share my desktop for my access over the network. Now I'm serving up the VNC java applet with apache, so I can go to http://mycomputer/login from anywhere and get my desktop! Neat stuff.

by nrp (not verified)

I might be being thick here, but how do you serve up the java applet with apache?

by Chris (not verified)

I am also quite interested about this. VNC Desktop sharing is nice, but I am the only GNU/Linux box running KDE 3.1, and in fact, almost the only GNU/Linux workstation in the office! What would be amazing is for the e-mail invitations to give the choice: http based java applet, or local vnc client. As it is, I suppose I can always customize the e-mail invitation to specify the correct information (ie, point it to the Java applet on my computer) but, I still am not sure how to set it up...

by loki gupt (not verified)

i want to share my desktop on network under win98 in java i need source code can u help me

by anish k abraham (not verified)

i am working on the project for desktop sharing and video conferencing on network under win98,2000 in java i need source code can u help me.

by mikhail (not verified)

hey there!
im a student n am working on video conferencing project...
can u hel p me...???

I don't think that adding a comment to a news article that's two years old will get you many responses...

You may want to take a look at http://www.kde-apps.org/content/show.php?content=10395
That's the only KDE-related video conferencing project I know of.

We are a browser based video & web conferencing company. Our product is very easy to use and cost effective. You can share video, audio, chat AND any show any application you want.

Please contact me at 877-634-6342 x 101 to get a demonstration of exactly how it works.

by sushma karki (not verified)

I am also doing project in video conferencing,I am a beginner and need your help so send me the demo(better if it is in VB.NET)

by anjana (not verified)

me too doing project in video conferencing. can u help me with code?

by Anish K Abraham (not verified)

For those who are still trying to prepare Desktop Sharing for distributed Networking on Java Platform, may be i could of some sort of help for them. Feel free to contact me, because i've created one, its a bit slow but it definitely works... and it can even manage more than one system Desktops simultaneously.

Best Regards
Anish K Abraham

by william (not verified)

I saw your post o desktop sharing in Java and would like some info. on it if still avaliable or upgraded?

by anns (not verified)

i am doing desjktop sharing..if u have some information,help me....

by gulmina (not verified)

I want to do a project related to desktop sharing. And i have no idea where to start from. So can you help me.

by anns (not verified)

i too do a project in desktop sharing//// dont have any idea abt dat...if u have some information, send me...

by anju (not verified)

I saw your mail that u have done desktop sharing.I am a fresher.can you help me by giving some idea about that.

by Lavitha (not verified)

Hi Anish,
If u have the details of desktop sharing, can u please send to me...
Regards ,

by Anish K Abraham (not verified)

Hi !
I dont usually check the replies over here. If you really need help , then try mailing me or join me for a chat at [email protected]
I'll be really happy if i could be of any help.

by Kishore (not verified)

Hi Anish,

Can you please help me out on how the desktop sharing application can be implemented using Java, like the technology to use at various levels.

Thanks & Regards,

by Safyan Shah (not verified)

Hi man, I am also doing this project in JAVA. But I still don't know, how to send those frames from Server to Client in RMI. Like we've seen that it's easy to invoke a method on server via interface but How does the Server sends message to Client?

by prats (not verified)

I m doin a proj on video conferencing in java. can i get the source code of it as i m facing problems in codin a bit. It ll help me to understand better

Hey anish k abraham and gupt,

I too am a student and working on a project which involves Java code for Powerpoint Presentation Sharing between remote computer and Client computers(Almost similar to a Desktop Sharing). Can anyone fo u in the group hel me out?

better to use teamviewer application for sharing desktop

by not me (not verified)

Oh, and I almost forgot: I want to congratulate you on the attention to usability and user experience you are putting into KDE's desktop sharing programs. If only every KDE developer cared this much about usability issues! KDE would become so easy to use a three-year-old could do it :-)

by Aaron J. Seigo (not verified)

animated demos are very cool. they are a terrific way to show people how the system works, both for PR and for educational purposes. hopefully we'll see more of these demos appear.

the desktop sharing stuff is awesome, too. one of my clients is using it extensively for tech support purposes and is just loving it.

so Tim: awesome work and thanks for all the code!!

did i mention how cool that demo was? ;-)

by Jonas (not verified)

Flash? What kind of proprietary junk is that? It doesn't seem to be available for my architecture.

Is there no open source / free software way to do the same thing? What about JavaScript/SVG? Would that be supported in, say Konqueror or Mozilla?

by Tim Jansen (not verified)

The SWF format is open, and there is a free library called library called libflash. It should be able to play the movie. You may need to write a plugin first though. Concerning SVG, afaik there is no free implementation that is mature enough.

by fault (not verified)

> It should be able to play the movie. You may need to write a plugin first though.

libflash also has a Netscape plugin.

by XavierXeon (not verified)

under http://www.macromedia.com/shockwave/download/alternates/#linux" you can download the latest flash player player for mozilla(linux) which integrates nicely in konqueror.

by Muad'Dib (not verified)

You obviously assume that everyone who uses KDE uses Linux. I use FreeBSD. I cannot view Flash movies. I will not entertain any arguments about Linux vs. FreeBSD.

by Roberto Alsina (not verified)

Quick translation: You use FreeBSD, and you DON'T KNOW how to see flash.
Because you actually can.

by Metrol (not verified)

Ohhh yes you can, just not in Konqueror. A couple of ways...

First, you can install /usr/ports/www/flashpluginwrapper that will allow you to view Flash with Macromedia's Linux plug-in within you natively compiled Mozilla. Works pretty sweet!

Secondly, you can install Netscape 7.0, which is a Linux based port. I haven't run this one myself, but in theory it should be able to properly embed any and all Linux based plug-ins in the ports tree.

Lastly, and most ickily (it's a living language. Deal with it), you can also install the Linux Netscape 4.7x. Ack, phewy. Still, the flash plug-in definitely works properly in it.

Heck, with the recent addition of KPlayer to the ports tree you can now even watch Quicktime movies within Konqueror. Took a little tweaking, but before too long I was watching movie preview right from Apple's web site.

Of course, with all these plug-ins that use Linux binaries that simply can't embed into natively compiled FreeBSD applications their's no good way to get everything working all in one browser just yet. Now if we could just get some more library wrappers like that flashpluginwrapper us FreeBSD folks would be stylin'!

by Jonas (not verified)

Sorry, no cookie. That is only a binary for Linux/x86 -- I don't want to think about at what speed it would execute under Bochs ;)

by Anonymous Coward (not verified)

Whahaha, you suck! Do you homework :P

by Paulo Junqueira... (not verified)

I don'ṫ know if it's possible, but an important feature in desktop sharing is to allow user to see only some programs(windows) like MS netmeeting. I use netmeeting a lot of times per week.

I know that is possible to execute a program an send it's window, mouse and keybord to other X server. It's implemented in the 3.1 solution?

Thanks in advance for your great work.

by Tim Jansen (not verified)

No. I havent spent much time thinking about it, but I dont know an easy way to implement it... one of the problems is that the X11 server can only sent screen data that's currently visible. The only clean ways that I can think off all include writing a specialized X11 server, a X11 proxy or a X11 extension.

by not me (not verified)

The X guys say it is a toolkit issue. They say that with the RandR extension, toolkits have all the information they need to migrate/duplicate a program between X displays. Maybe support should be added in QT? I guess that wouldn't be the best practical solution, though, since then only QT programs would be able to be shared; other apps would have to be re-written. And how would you tell a program to duplicate itself? Instead of having one program that could migrate others around, every program would have to migrate itself. An X extension would be better, but it doesn't sound like you'd have the support of major XFree developers.

by Tim Jansen (not verified)

RandR helps when you want to migrate an app from one X11 server to another (because it can reconfigure the parameters). But it does not help if you want to have the app on two X11 servers simultanously, or to get pixmap of the application's window (which is needed for VNC).

by Andrew (not verified)

Why not use XVFB and set up user's desktop over there?

by mike ta (not verified)

This is off-topic really, but would it be possible (in principal even:) to implement a sort of network/pass-through windows display driver. What I mean is, a driver where the calls into it are all passed down to the "real" display driver, and also sent off over the network. That way we could avoid all the screen scraping that VNC has to do?


by Tim Jansen (not verified)

Yes, xf4vnc.sourceforge.net does this (for the screen, not individual windows). There are several ways to do this, but they all require changes in the X11 server or its drivers.

by mike ta (not verified)

Actually, I meant a Windoze driver

by Andrew (not verified)

Isn't that exactly what Citrix and WTS do?

by derek (not verified)

Does the KDE VNC app try to do any ssh tunneling of the VNC connection? It would be very nice if it set this up (semi)automatically for the user.

by Tim Jansen (not verified)

IMHO SSH tunneling is a very crude hack, both technically and from the user's perspective (because you need to authenticate twice). A cleaner solution would be to use SSL...

by js (not verified)

You don't *have* to authorize twice. you could have krfb bind to only accept local connections, then someone ssh tunnels to the box and it just works. Then using the invitation cookies it would keep out other local users from nabing your session.

by Tim Jansen (not verified)

If the VNC server does not require a password, everybody with an account on the machine would be able to join every desktop.

To solve this you would need some challenge-response technique (for example krfb writes cookie to user's home dir, krdc reads it over ssh and uses the cookie as password). But then the solution becomes more complicated than SSL and not backward compatible with existing vnc servers anymore - thus the only two advantages of ssh would be lost.

by Leigh Upton (not verified)


is it possible (desirable or not) to bind to the loopback interface?


by Tim Jansen (not verified)

ATM kinetd does not support this.