Is there a Web Service That Allows Annotation of PDF Files?

Is there a web service that allows (in-browser only) annotation of pdf files?

The question is abstract. I am assuming you have a PDF file and you want the link to be shared with others. If you want to do this on your website, you can very well use your website hosting space to store and provide the links on your website. It will be treated as any other file. Based on your technology framework you can figure out your file paths. In case you are talking about sharing your PDFs as part of collaboration with other people, you can use any cloud service. I always use google drive to do this but I am sure there are more cloud providers for this as suggested. If you put more specifics in your question, it will help .)