Freeplane comes with it's own version of the Groovy library. If you want up update it to a more recent one you can do that quite easily. It just takes the following steps:

  1. Download Groovy binary distribution package (e.g. groovy-binary-1.8.0.zip) from http://groovy.codehaus.org/Download.
  2. Extract the groovy-all Jar from the package
  3. Replace the old groovy-all Jar with the new one.

For Linux (non-deb version)

We assume that Freeplane is installed to /opt/freeplane:

$ unzip groovy-binary-1.8.0.zip groovy-1.8.0/embeddable/groovy-all-1.8.0.jar
inflating: groovy-1.8.0/embeddable/groovy-all-1.8.0.jar

$ sudo mv /opt/freeplane/plugins/org.freeplane.plugin.script/lib/groovy-all.jar \
/opt/freeplane/plugins/org.freeplane.plugin.script/lib/groovy-all.jar.orig

$ sudo cp groovy-1.8.0/embeddable/groovy-all-1.8.0.jar \
/opt/freeplane/plugins/org.freeplane.plugin.script/lib/groovy-all.jar