So, I tried to upgrade to 4.9 this afternoon, and i go through the entire installation process only to find that when i try to open Limewire, it tells me:

"Could not launch the application because it requires a version of Java that is not installed.

This application requires Java 1.4.1. or later, but only Java 1.3.1 is installed. Updating to a newer version of Mac OS X may resolve this."

I tried updating the Java on my computer but it turns out that I do indeed need to have a more recent version of OS X to upgrade Java.
Can anyone help me out with this? I really don't want to spend the money to upgrade operating systems. Is it possible to somehow just go back to the last version of Limewire? Please help!!

Java 1.4.1 for Mac OS X 10.2.6 or later:

http://docs.info.apple.com/article.html?artnum=120242

Note: this was the first and last Version of Java 1.4 for Mac OS X 10.2.x. Upgrade to 10.4 if possible.

Thanks so much, it worked! I was pretty worried I wouldn't be able to use Limewire for a looong time. Thanks again, you're help is really appreciated.

The reason LW 4.9 requires Java 1.4 or later is that starting with Java 1.4, Sun introduced a much more efficient way to handle network traffic (java.nio, which stands for New Input/Output). This allows LW to handle more connections for the same ammount of processor usage.

In my opinion, Sun should have had their "New Input/Output" package in Java from the start; it's technology that other programming languages/systems have had in their standard libraries since the 1970s.

In any case, as mentioned above, Java 1.4 is avalable for OS X 10.2.9 and later.