Just a starter note on which languages are installed on vanilla modern OS installations:
—–
MacOSX (10.9+) – bash, html, java, javascript,objective-c, perl, python, php, ruby
Windows 8 – batch, html, javascript, jscript, vbscript
Linux Ubuntu / Debian (14.04 Trusty) desktop – bash, html, javascript, perl, python
Linux Redhat / Fedora – bash, html, java, javascript, perl, python
Linux CoreOS – bash, dockerfiles
Freebsd – bash, perl, python
IOS – html, javascript, objective-c
Android – html, javascript
Have a think on which language to write your next application in to get the widest audience on basic installations. The alternative is to release pre-compile distributions or convince your target audience to install interpreters such as nodejs (V8), luajit, pypy.
Do note its good to check the versions of default installations. For example, python2 (2.7) is widely default installed, however python 3 is the recommended current default language. Python 3 is not backwards compatible which makes things a bit iffy.
Overview of Languages
bash
Good – basic, simple, wide supported
ruby
Good – easy syntax, simple, good package manager
python
Good – easy syntax, wide supported
Bad – confusing package manager(s), no backwards compatibility for major versions
javascript
Good – wide supported, good package manager
lua
Good – simple, fast, good structure, embeddedable
Bad – limited syntatical/functional shortcuts, strange syntax
c
Good – very mature, wide support, fast, embeddedable
Bad – limited syntatical/functional shortcuts
java
Good – wide supported, fast, mature
Bad – extremely large collection, missing central repository