Personally I'd vote for javascript, like mentioned above most would probably vote for what they are most familiar, and I can't say my opinion is any different from that. But Javascript is fairly powerful language, is not that hard to learn (I've coded my own yahtzee game in it for fun, I'm still in the process of learning perl, I know its a powerful language but it takes some getting used to, for me anyhow) and it has plenty of references out there. Otherwise I'd say go with perl

[Quick Edit:] I think support for another language would be a very good thing for savitar. I've always loved rapscallion for its range of features that even today 8 years after it lost any development are still quite good, but I moved to Savitar when I moved to OS X and have enjoyed it since, though I have used other clients such as Mudwalker, GGmud or Atlantis for their other languages that I can write scripts for, either Lua which has a syntax somewhat similar to Javascript, or Perl respectively and would be a great thing for savitar to have as well.