For installation of netbeans package you need JDK 1.6 installed on your Fedora box. on Fedora 9 you are having already installed JDK 1.6 so you need to update the installation only.
Use following command for installing or updating JDK installation.
#yum update java-1.6.0-openjdk-devel
#yum install java-1.6.0-openjdk-devel
Than go to this URL (http://www.netbeans.org/downloads/index.html) and download the .sh file which you want install on your Fedora 9 box.
As per my view Netbeans supports for Rails and PHP and Netbeans is best IDE for Rails and PHP.
For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make the installer files executable by using the following command:
#chmod +x netbeans-6.7.0-ml-ruby-linux.sh
This command i given for ruby IDE, you can choose your IDE or as per file name.
Than run the installer file
That sit netbeans installtion will start to PC. After installation you can start netbeans from programming menu.