One other version has no dependency on X, and starts up much faster, but it cannot be used with X, because there's no way to have a shared library have a weak reference to another shared library with the current ld. The other other version dynamically references Motif, but will use your version of Motif at runtime instead of the statically bound version. This allows you to use your own local Motif shared library instead of the statically bound one, so you can experiment with LessTif, and can take advantages of more recent versions of Motif. Starting with the 1.1.7 v1a port of the Java Virtual Machine, we have added native thread support. Native threads, on the other hand, use the operating system to do the task switching.
Native threads do have some limitations relative to green threads.
They require more overhead and are limited to the number of processes your Linux kernel supports. Native thread support is new as of 1.1.7 v1a due to the wonderful effort of Phill Edwards. To install the native threads package, you need to first download the JDK, JRE, RT and install that. Next, you need to get the matching native threads package and install that into the same location. Also, at this time there is no native threads support for libc5 systems.