At present there is no magicjack client software for linux or ubuntu.
But the good news is Magic jack for linux (will run on ubuntu) is under development and expected to be released in the first quarter probably march of 2010 according to magic jack website.

Ubuntu 11.04 code named natty narwhal is released download ubuntu 11.04
Read ubuntu 11.10 reviews and share yours now!!
This is a little late but .... never the less. It is now almost 2012 and still no Linux for magic jack ... I posted my chat with support. I honestly think the have dumped the idea now that MJ Pro is out .. too bad.
Dory: Hello, how may I help you?
- Visitor 23 weeks 2 days agoKevin: Hi
Kevin: quick question
Dory: Sure, go ahead please.
Kevin: Will there ever be Linux Support (debian/Ubuntu) for magicjack. I just upgraded to pro however all my systems are linux
Dory: We do not have that information yet, Kevin. Please check our website from time to time for future updates.
Kevin: I have tried using WINE ... this does not completely work. and I dont want to use all my resources with vmware.
Kevin: I have. It has said the same thing for two years
Kevin: is there any ETA
Dory: We are also waiting an update from our Engineers regarding with that matter.
Dory: But there's no update coming from them yet.
Kevin: Im an open source developer. Is there somewhere I can go to help with the process?
Dory: One moment please...
Dory: Please check my chat... regarding Linux.
Kevin: Im not understanding.
Dory: Please disregard the message above.
Kevin: lol k
Kevin: wrong window
Dory: I am sorry for that.
Dory: One moment please...
Kevin: nw
Dory: Thank you for waiting. I'll be with you in just a moment.
Kevin: k
Dory: I'm sorry for the delay. I'll be right with you.
Dory: I will be right with you.
Kevin: k
Dory: Thanks for patiently waiting, Kevin.
Dory: As I have confirmed here, we don't have the information yet on when are we gonna support Linux with magicJack. I understand that you keep on checking on this. Please do not worry as magicJack is trying everything to offer that feature.
Dory: Unfortunately, it is not yet available now.
Dory: You can try to check back our website from time to time for updates.
Dory: We really appreciate your offer in helping with that feature to be possible with magicJack.
I found a way to run Magic jack with Ubuntu without the jittery audio on either end.
- Mchswn 28 weeks 6 days ago1.Download Ubuntu 11.10 Oneric Ocelot and install it
2. Download VirtualBox 4.0.14 the last edition of the 4.0 series it can be found under the older versions on the download page. Then Download the extension pack for the 4.0 version only.
3. Next make a virtual machine.
4.Now you will need to do one thing since Ubuntu 11.10 has done away with the User groups box. Here is where you get the instructions to add yourself as a Vboxuser. https://help.ubuntu.com/community/VirtualBox/USB.
5. Once added as a user go to settings then to USB. Tick the box ENABLE USB CONTROLLER (ONLY) .**** Leave the Box (Enable usb 2.0) UNCHECKED.***
6. Now Install your favorite Windows OS, (Caution) I have only tested this with Windows XP. If you use windows 7 or vista OS in the VM please let me know how it works.
7. Once Windows is installed start the box and unplug and plug the Magic Jack back in.
The Magic Jack will load and you are ready to make calls.
August of 2011 still no linux driver. Magic Jack website still says "future"
- Visitor 38 weeks 3 days agoThe bad news is, that date has been moved already two years from where it was first set. And, oh yeah, March 2010 was 3 months ago and counting. Doesn't surprise me at all.
- Visitor 1 year 47 weeks ago