Thread:SEOkitten/@comment-5973717-20150913153211/@comment-26321732-20150915004840

It is tough to assess the SEO impact of additional programming languages without examining the source code and/or creating a testing framework. Keep in mind that, as a general rule, internal links not fully expressed in HTML are invisible to search engines.

JS is difficult to impossible for search bots to read, so I imagine CoffeeScript would pose similar challenges. I am not familiar enough with Common Lisp to provide guidance.

Ours is an older code base with loads of custom script, so I share DaNASCAT's concerns that additional unsupported languages (or languages with limited support) could lead to issues for both human users and search bots.