I am curious why you asked about alternatives instead of Zotero if it's your first time seeing it. Zotero is simple and extremely popular. With third-party exte

I am curious why you asked about alternatives instead of Zotero if it's your first time seeing it. Zotero is simple and extremely popular. With third-party extensions, it has enhanced capabilities. It has a PDF viewer and you can annotate the files. Finally, there is an iPad app that works very well. Edit: A very popular thread from just 8 months ago - https://news.ycombinator.com/item?id=30714121 https://news.ycombinator.com/item?id=30714121