No Java 1.2.2 JVMs available support SMP kernels. So, you must install a 1.3.x JVM if you're using an SMB kernel, especially if your machine contains multiple processors, since this exercises SMB threading.

Early releases of IBM JDK 1.3.0 do NOT support SMP kernels. I'm told the most recent release does support SMP but I have not verified this myself.

Sun and Blackdown 1.3.0 both support SMP kernels.

Since JBuilder 4.0 for Linux is bundled with IBM's earlier 1.3.0, you must install an additional JVM for both JBuilder and your own Java applications to use.

  Since JBuilder 3.5 is bundled with Sun's 1.2.2, your only options are:

  1) Run JB35 on 1.3.0 (not a supported option, and not without problems) 
  2) Download JBuilder 4.0, and replace its bundled IBM JVM with either the
     latest IBM JVM, or with Sun or Blackdown 1.3.x, all of which support SMP.