I want to make many large software systems which requires the functions that have features like English Grammar Check and all other validations/manipulations that can be done in English. Is there any package available in any programming language that gives me these resources? Just imagine I am making a software like MSword, and I want to add Grammar Validations in my software same as in MSword, is there anything available or I have to code everything from scratch? How hard it would be according to you? How much time would it take?
There is LanguageTool for Java. It supports many languages including English and you can add your own rules. Just don't expect the check to be perfect; Word's isn't either.