Open source software good for new company?

My old company used a good, but a little expensive pos software named multiflex pos by Microhouse systems. After leaving that company, I am in the developing stages of my own e-commerce company focused on my locality. I needed a low expense pos software and after looking for some time, I found nopCommerce. It looks really good and open source which makes it better. But I am a little concerned about if it affects my site in any way. Can anyone advise me about it?

RE: "if it affects my site in any way"
nopCommerce is a fully self-contained e-commerce shopping cart application.  So, it depends on what your "site" is.  If it's just a CMS, then you could have links to nopCommerce as the cart/store.  If your site is a cart/store, then you would probably convert it entirely (migrate).  In either case, you will need to enter all the products (there is an Import), deal with conversion of existing customers (if needed), etc.