If you would like to write your own programs that use the primer design algorithm on this site, the rf-cloning server can handle XML requests using the Simple Object Access Protocol (SOAP).
The wsdl file is at http://www.rf-cloning.org/classes/rf_cloning.wsdl
I have also written a client class in php: http://www.rf-cloning.org/classes/rf_cloning_client.txt.
As well as an example Perl client: http://www.rf-cloning.org/classes/perl_soap_client.txt.
For a functional Python3 client, try out this: http://www.rf-cloning.org/classes/python_soap_client.
There are some details on usage in the forum.
If you write a client class in another language and are willing to share, I'd love to hear from you.