Whilst busily reading up on Scala and Groovy and other languages that ran on the JVM, I had a thought with regard to the scripting language that the network architect at work now advises is included in the Cisco ISG/ASR’s. Cisco now have the Tcl scripting language installed on the IOS. One application is used to control phone IVR and voicemail systems which is a pretty neat feat.
Tcl itself doesn’t seem to be much of a mystery language either and should be easy for anyone coming from another scripting language background.
There is a Jacl for the JVM as well and also a means to bring Java code to a Tcl interpreter via Tcl Blend.
You can use Tcl to script EXEC level commands on a router such show version and int fa0/0 type stuff as shown here.
There is also a Cisco article about getting started with Tcl on the routers.