Tag Archives: Linux

Firefox Tips for Spell Checking and Backspace Key

There are a lot of hidden preferences in Firefox that are available by entering about:config in the browser’s address bar and pressing the Enter or Return key. Here are some tweaks that I find particularly helpful.

To change a preference in the list, double-click on it. To filter the list, type any part of the preference name in the Filter box.

  1. browser.backspace_action
    By default on Windows and Mac OS X, hitting the backspace key causes Firefox to go back one page in the browser’s history. Changing this setting’s value to anything greater than 1 (Firefox on Linux defaults to a value of 2) will disable this behavior to prevent accidentally changing pages while typing in a form or Flash program.
  2. layout.spellcheckDefault
    The default value of 1 enables spell checking in text areas. To have Firefox show incorrect spelling in text input fields of forms as well, change this value to 2.

Changes to these settings take effect immediately. The spell check one may require that you reload a page that was open before the setting was changed for it to take effect.

How to Run Multiple Firefox Profiles Simultaneously

As you probably know, Firefox supports the creation of profiles so that different people can have their own browser configuration (buttons, add-ons, font size, etc.). If you’re not familiar with this feature, see How To Manage Profiles at the Firefox help site. A feature that’s more obscure is that you can actually run more than one profile at the same time.

Why would you want to run profiles simultaneously? I use the feature primarily so that I can check that pages look correct on a clean Firefox profile as well as on my heavily souped up one with lots of add-ons. You might also find it useful to have profiles with different add-ons for different tasks and then start one or more as needed.

Normally, if you start Firefox when a copy is already running, it’ll just start another window using the current profile. To start a completely separate instance of Firefox, add the -no-remote option. In Windows, you can either do this by selecting Run from the Start menu and typing in the entire command, or add the option to the shortcut that you use to start Firefox. On Linux, just add the option to the command line or if you’re using a GUI (e.g. Gnome, KDE, Xfce) adjust the command assigned to the desktop or menu icon that you use to start Firefox.

For example,

firefox -p Profile_Name -no-remote

will start a new instance of Firefox with the profile named “Profile_Name”. If, on the other hand, you want to choose the desired profile from the Profile Manager window, use

firefox -profilemanager -no-remote

Now you can start as many different profiles as you like.

Have a novel way to make use of profiles? Leave a comment.

VirtualBox: Free Virtualization on Windows, Linux and Mac OS X

Innotek released version 1.5.0 of VirtualBox, their open-source virtualization product, the other day. In addition to many fixes and improvements, this version includes seamless window virtualization when running Windows in Linux so you can have Windows applications running right beside Linux ones.

I guess you could call this the summer of virtualization with all the buzz about saving energy via server consolidation, running Windows in Mac OS X with Parallels Desktop and VMWare going public with extraordinary gusto. However, what if you want to get into the game without using closed source software or without spending a lot of money while having support for many platforms? That’s where VirtualBox comes in.

VirtualBox runs on Windows, Mac OS X and Linux and enables you to use a variety of guest operating systems in it including DOS, Windows, Unix, Linux, Solaris and OS/2. As I mentioned before, when running Windows inside VirtualBox on Linux, through seamless virtualization Windows applications will run right beside Linux ones on the Linux desktop. For other operating system combinations, the guest OS will still have its own desktop window like it did in VirtualBox 1.4.0.

If you’re currently running Linux, many distributions already have VirtualBox available for installation from their software repositories. For example, in Ubuntu, Kubuntu or Xubuntu, just run Synaptic or Aptitude and choose VirtualBox from the list of packages. Otherwise, you can get it from the VirtualBox download page.

Open Source Alternatives


Are you looking for an open source alternative to a well-known commercial application? Do you use an open source program and want to see what commercial product is similar? Well, check out Open Source Alternative, a directory of cross-referenced open source and commercial applications.

You can browse by categories such as business, communications, multimedia and web development or search the directory by application name. On a program’s detail page will be a short description, a link to its web site, the platforms that are supported (Java, Linux, Mac, Unix and/or Windows), and a list of alternatives. For a commercial product, open source alternatives are listed. For an open source product, commercial alternatives are listed. I’ve found it to be a very handy resource for locating software solutions.

Encrypt Synergy Connections with SSH

If you’re using Synergy, all of your keystrokes are sent over the network as cleartext because Synergy does not provide any encryption. In other words, unless you’re using a private network to connect your computers, anyone can sniff the data to see what you’re typing to client computers including passwords, credit card numbers and other sensitive information.

The good news is that it’s not too difficult to prevent snooping by using OpenSSH. The Synergy Network Security Guide shows you how to do this on Linux/Unix-based systems (which should work similarly on Mac OS X).

The bad news is that if your Synergy server or client is on Windows, setting up OpenSSH isn’t as straightforward. I was in this situation for quite a while and, after several unsuccessful tries, I put it on the shelf for a while. Well, tonight I found a very good resource to get OpenSSH working on Windows. I successfully set up a Synergy/OpenSSH server on a Windows XP laptop and connected a Linux client to it.

Note that if you’re using QuickSynergy to set up a client on Linux or Mac OS X, you can simply enter localhost as the server name in the QuickSynergy dialog instead of running synergyc -f localhost as described in the last step of the Synergy Network Security Guide.