I'm the founder of https://kontxt.io and I initially built it as a solution to effectively save and share information in context. You can save links, clone websites, convert PDFs (and most other documents since they can be converted to PDFs) to websites that's enhanced with a real-time collaboration & note taking layer. Tag everything from documents to page parts. Organize with folders. Share documents and folders with google doc like share permissions. You can upload URLs and documents directly, use the chrome extension, or even add the collaborative features to your own sites.

Check it out and let me know what you think. I'll be adding search soon, a public feed like Twitter for discovery, and a way to extract and use highlights across documents. If you try it out, like it, and want to start using it, I'll add basic search across titles and tags for you this week.