OSGi

It is originally devised for embedded device market. Hot-pluggability is one of the feature envisaged.  It refers to a systems that can alter its capbility without reboot.  In the embedded device arena, hot pluggability is not common in 1999.  As these devices has limited processing power and memory, another feature envisaged is auto-discovery and reusing software.  OSGi defined itself as the dynamic module system for Java.