Imagefilter uses the Realbasic Script language for its scripts and for the plugins, expanded with Imagefilter functions. The following text will only explain the most important functions. For full documentation, refer to the Realsoftware website: http://www.realsoftware.com.
The script is one main function, for which you do not define a header and a footer. Inside the script, however, you can define functions before the code of the main function.
While you are writing the script, you may want to put the script filter on bypass, so that it is not executed with invalid code.
This simple script will just print "Hello World" to the console:
print "Hello World"