Rob Lougher has released JamVM 1.3.1, a free (GPL) Java Virtual Machine that "conforms to the JVM specification version 2 (blue book). In comparison to most other VM's (free and commercial) it is extremely small, with a stripped executable on PowerPC of only ~100K, and Intel 80K. However, unlike other small VMs (e.g. KVM) it is designed to support the full specification, and includes support for object finalisation, the Java Native Interface (JNI) and the Reflection API." Like most free VMs it relies on the GNU Classpath library. 1.3.1 provides various optimizations and bug fixes. JamVM only interprets code. It does not have a Just-In-Time compiler.