Google Talk: Run Multiple Instances or Login as Multiple Users

If you have several Google talk accounts, you may want to run multiple instances of Google talk at once. Here’s how to do it.

Many users, including myself, like to have several different personalities on IM–Work, play, etc. By default Google talk with only allow you to run instance of the program at a time. Here’s how to get around that…
Run Google talk with the following switch: /nomutex
If you installed Google talk to the default location, you can easily create a shortcut to this setting.

1. Right-click on the desktop
2. Select New
3. Select Shortcut
4. Paste this into the text box:
"c:\program files\google\google talk\googletalk.exe" /nomutex
5. Click Next6. Name it whatever: Google Talk Multiple, etc.
7. Click OK until you are done.

How to Run Multiple Yahoo! Messengers and Login to Multi Yahoo! Messengers Accounts

For Yahoo! Messenger with Voice 8 users, it’s now possible to run multiple instances of Yahoo!. Messengers (polygamy feature) and log into multiple Y!Msgr accounts with just a simple registry hack. So if you need to open and log-in multiple Yahoo! Messenger accounts as you have a few Yahoo! ID or various other reason, just use the small registry registration file below that once click, will modify and merge the registry setting required to run and execute multiple Yahoo! Messengers at the same time on a computer.

Download ym8multi.zip, extract it and run “ym8multi.reg” contained inside the archive. Once the registry is patched, you can now starting and running multi Yahoo! Messenger with different login or Yahoo! ID accounts. If you want to uninstall the patch/hack, download the ym8multi_uninst.zip uninstaller which contains ym8multi_uninst.reg. Once double click on this uninstaller registration registry value file, it will edit the registry value and set it to disable the ability for Y! M 8 to launch multiple copies of instances.



If you prefer to edit and change the registry setting yourself manually, without using the above registry registration file, simply launch the registry editor (type regedit at Run command), and navigate to the following registry branch:

HKEY_CURRENT_USER\Software\yahoo\pager\Test

Then, on the right pane, right click on the registry editor and select “New”, then create a new DWORD registry value. Name the new registry key as Plural, and assign it the value of 1 (decimal). If some case, the value of 2 should also works. To disable or disallow multiple instances of Yahoo Messengers, simply change and set the “Plural” registry key’s value to 0, or delete the “Plural” key.

Marker Interface in Java

Marker Interface most of the people know the definition, but many of them are not aware of the purpose of the Marker Interface and how it works. Very often I heard the question from my friends that the Marker Interface doesn't have methods then what is the use of Marker Interface.

One of the basic feature of Java Programing Language is that it mandates a separation between Interfaces and Classes. Interfaces are used in Java to specify the behavior of the derived class.

While working on the Java Programing Language many of the programmers might have observed the Interfaces which doesn't have no behavior. In other words they are just empty Interface definitions. These Interfaces are knows as Marker Interfaces.

Basic Definition: Interfaces with empty body.
Example: Serializable, Cloneable, Remote, EventListener


Marker Interfaces are also called as Tag Interfaces because they tag all the derived classes into a category based on their purpose. If we consider a real time example for this scenario, lets pick Cloneable from the abouve examples given. All classes that implement Cloneable Interface can be cloned by calling clone(); method. Now the Java Compiler checks to make sure that if the clone(); method is called on a class and the class implements the Cloneable Interface. If we have the Object obj and call clone(); method on this as

MyObject obj = new MyObject();
MyObject ref = (MyObject)(obj.clone());

Here if the MyObject doesn't implement the Cloneable Interface and Cloneable is not implemented any of the super class that MyObject inherits from, the compiler will mark this line as error. This is because the clone() method may only be called by objects of the type Cloneable.

Here our Cloneable Interface is an Interface with empty body, but still it serving a major role.

To create a copy of any Object, in our case we have MyObject to create a clone for this Object we need to have a clone(); method which should implement Cloneable Interface.

The above scenario clearly states that we are marking the class Cloneable so that the Object can be Cloneable. For this purpose we have Marker Interfaces in Java.

When ever we implement Serializable, Cloneable JVM understands that this thing is to be serialized or cloned and no methods involved in this process.

Hope this article will clear your ambiguities about Marker Interfaces.