Friday, January 27, 2012

Moonlight in Firefox or Chrome on Ubuntu

Moonlight is a Silverlight alternative available for Linux users from the fine people at Novell.

This How To is designed for use on Ubuntu 11.10 using either Firefox 9.0.1, or Chrome (Chromium) version 15.

First I installed libmono-wcf3.0-cil. If you use Synaptic or Ubuntu's Software Center, you can find this by either searching for mono or Moonlight.

You can also install this with apt-get by typing the command: sudo apt-get install libmono-wcf3.0-cil in your terminal window. (Control alt t, unless your using xfce.)

*** This section is for Firefox only ***

I installed a Firefox plugin called:

Disable Add-on Compatibility Checks 1.3
by Kris Maglione

Reinstates the extensions.checkCompatibility preference without respect to the current application version.

This is needed because technically the Moonlight plugin is not yet considered compatible with Firefox 9.0.1., as well as many other versions of Firefox.

I have never had a problem with Moonlight running in this fashion though.

Firefox will ask you if you trust these plugins. Say yes to continue, or this process won't work.

I have never had any problems with viruses or any other intrusions from these authors.

You can find "Disable Add-on Compatibility Checks 1.3" here:

Once that is installed, then we want to install the Moonlight plugin.

*** This section is for both Firefox and Chrome ***

You can get Moonlight here:

Again Firefox asks if you trust the author, which in this case is Novell, who is very trustworthy.

Chrome will display a warning on the bottom of the page. You must allow the download for this process to work.

Once this is accomplished you will need to restart Firefox. Chrome should not need a restart.

If you want to test your newly installed Moonlight plugin, I suggest using this page:

I suggest you use this test: Silverlight 3.0 (CLR, CacheMode="BitmapCache")

The reason I suggest that particular test is that your new Moonlight plugin should now handle Silverlight 3.0 extensions with ease, so this is a decent test for our new plugin.

If you see the balls floating, you are the proud owner of a functioning Moonlight plugin.

I hope this has been useful to you, if you have any questions, please feel free to email me at


  1. Great post - thanks.

    They key was the Disable Compatibility Checks.

  2. I am glad it worked for you! :)

  3. This comment has been removed by a blog administrator.

    1. Please do not add advertisements to this blog unless it has something directly to do with the article in question.

      I did look at, and it does have it's uses, so thank you for bringing it to my attention.

      This is just not the place to do it.

  4. Thanks for the tip -- install Disable Compatibility Checks plugin!

  5. Good tips to solve
    this problem of Mozilla is not opening...greatly appreciated!!

    Firefox Technical Support

    please visit the link.