Article spining program1 , word replacer

Hello, I would like an already made article spinner program, which replaces common words with other common words, and phrases. I'm looking to make at least 1 or 2 replacement per sentence, Inport form, could either be ./program filein fileout or I'll add it in as a module to my current program as a function where it'll spin on the fly. If you have a ready made program, please list the details, and features. Thanks