Javascript interpreter to replace Python
I personally use SpiderMonkey, but here's an extensive list of ECMAScript shells
Example spidermonkey install and use on Ubuntu:
$ sudo apt-get install spidermonkey$ js myfile.jsoutput$ jsjs> var f = function(){};js> f();
Of course, in Windows, the JavaScript interpreter is shipped with the OS.
Just run cscript or wscript against any .js file.
There are four big javascript interpreters currently. V8, Squirrelfish, Spidermonkey and Rhino. I think more important than performance is how well it integrates into existing infrastructure, and I guess Rhino with its bridge to Java wins here.