This is a walkthrough for setting up a portlet development environment With IBM Rational Application Developer (RAD) 8.
Step 1 - Verify you meet the System requirements for Rational Application Developer 8.
Step 2 - Download RAD 8 install package
Trial version can be found from http://www.ibm.com/developerworks/downloads/r/rad/?S_CMP=rnav
Step 3 - Install RAD 8
Lunch the IBM Installation Manager to install Rational Application Developer for WebSphere, in Features screen, select Portlet and Portal development tool. If you don't have a local portal server installed, make sure the "Tools for developing applications without a local server installation" option is selected, as shown in below.
Step 4 - Setup a Portal Server in RAD
1) From the RAD menu, Window -> Show View -> Servers
2) Right-click the server view and click New -> Server.
3) On the Define a New Server page, select WebSphere Portal Server
4) Follow the New Server wizard and provide the WebSphere Settings, WebSphere Portal Settings and Properties Publishing Settings.
Step 5 - Verify the setup
Right-click the Portal server in the server view then do a start and stop to verify the server setup.
Congratulations! Now you have set up a portlet development environment in RAD, and you are ready to start portlet development.