.NET在winform中打开PDF，没有外部依赖

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 bloated to me and I would be relying on it being installed. Is there a nice lightweight alternative where I could just include a dll in my project or similar avoiding external dependencies. Is there a FREE library which will allow me to