Qiqqa is by far the strongest solution for research and managing pdf's. Zotero, named as a comparison is weak as it does not allow pdf;s to be loaded into its interface - you need to use a pdf reader, which defeats its whole purpose. With Qiqqa documents in a library can be searched together. It has excellent maps of your libraries. It is not prefect, having a few glitches, but still is the only one of its kind.
Based on our record, BibSonomy seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Oh, I miss del.icio.us - UI / execution / social discovery, all those fantastic finds... :) I love tagging a lot, but the problem with tagging is that only a handful of software/services use look-up for tag1 AND tag2 (AND tag3...) filtering. It's such a simple concept to filter all used tags based on already selected if I'm making a query using tags. I can not understand how people don't get that without this... - Source: Hacker News / about 2 years ago
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .
Citavi - Citavi is a program for Microsoft Windows that manages literary references and organizes organizational knowledge.
Paperpile - Clean and simple and reference management for the web. Sync your PDFs to Google Drive and cite your papers in Google Docs.
Docear - Docear