How do you use link on GBA emulators?

My question is in the subject title.Any help?

I'm sure it can be done by using Visual Boy Advance.
Run two VBA emulator at the same time, I guess..

VBA can do it with a program called VBA Link over TCP/IPNo$GBA can load multiple instances of the game (up to four total I believe) by going into the settings and changing the number from 1 to 2-4. Then you just open the ROM in each one, reset them all, and they should be able to link to each other. I have seen videos of it used on the Zelda game Four Swords.