nodo - Manage your daily tasks in the command line
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Simply.Digital - Goals & Tasks - Todo list to track your time & help set meaningful deadlines
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.
Proud for Mac - Break down tasks & boost your productivity
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .