Is there a FREE library which will allow me to open a pdf and show it on a winform project. I know I could open it in adobe reader or something but it always seems so bloate
I would look into Foxit Reader as a lightweight alternative to Adobe Reader. It consists of a single .exe file that you can bundle with your application and thus shouldn't require any installation. According to their EULA this is allowed, as long as your application is not installed on mobile devices. All you would have to do is launch the reader as a new process, pointing to the appropriate pdf. Obviously the downside to this approach is it won't be integrated into your application's interface.