Litmaps - Search scientific literature with interactive citations map
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
Deepnote - A collaboration platform for data scientists
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Amie - GitHub for research and data science
Qiqqa - Qiqqa is a free research and reference management software. It can be used in many organizational projects from the academic to the personal to the business endeavor. Read more about Qiqqa.