Script loading
When you run liquidsoap for streaming, the command line has the following form:
$ liquidsoap script_or_expr_1 ... script_or_expr_N
This allows you to ask liquidsoap to load definition and settings from some scripts so that the become available when processing the next ones.
For example you can store your passwords by defined the variable xxx
in secret.liq, and then refer to that variable in your main script 
main.liq. You would then run liquidsoap secret.liq main.liq. If you ever 
need to communicate main.liq there won't be any risk of divulgating your 
password.
The pervasive script library
In fact, liquidsoap also implicitly loads scripts before those that you specify 
on the command-line. These scripts are meant to contain standard utilities.
Liquidsoap finds them in LIBDIR/liquidsoap/VERSION where LIBDIR depends on 
your configuration (it is typically /usr/local/lib or /usr/lib) and 
VERSION is the version of liquidsoap (e.g. 0.3.8 or svn).
Currently, liquidsoap loads pervasives.liq from the library directory,
and this file includes some others.
You can add your personal standard library in that directory
if you find it useful.