Here is a RESTful web service that provides global DNA sequence alignment implementation as a service.
The service can also be called directly: http://mindwriting.org:8080/BioREST/resources/alignment?sequences=GC,C returning the response as text.
This implementation uses gap penalty score=2 and mismatch penalty=1. See here for a more sophisticated implementation (ie. with gap extension penalties and so on) from the The European Bioinformatics Institute.