Qiqqa is free award-winning knowledge-, research- and reference management software. If you're serious about getting the most from managing your publications, PDFs and bibliographies, Qiqqa is for you. Superb reference and document management. Import PDFs into separate libraries. Automatic OCR and tag extraction. Qiqqa helps you populate missing metadata for millions of research papers. Full-text search, duplicate paper detection, inbound and outbound links, and much more.