Latest version is JamVM 2.0.0, released on 30th July 2014. JamVM is compatible with the class-library from OpenJDK 6, 7 and 8 (the latest).

I backport jamvm and classpath to current version.

First remove old one if it is installed.

opkg remove jamvm
opkg remove classpath
cd /mnt/sda1
wget -O  classpath_0.99-1_ar71xx.ipk --no-check-certificate
wget -O  jamvm_2.0.0-1_ar71xx.ipk --no-check-certificate
opkg install classpath_0.99-1_ar71xx.ipk
opkg install jamvm_2.0.0-1_ar71xx.ipk

Test jamvm installation.

root@Arduino:~# jamvm -version
java version "1.5.0"
JamVM version 2.0.0
Execution Engine: direct-threaded interpreter with stack-caching
Compiled with: gcc 4.6.3 20120201 (prerelease)

Boot Library Path: /usr/lib/classpath
Boot Class Path: /usr/share/jamvm/