XournalppXournal++ is a handwriting notetaking software with PDF annotation support. Written in C++ with GTK3, supporting Linux (e.g. Ubuntu, Debian, Arch, SUSE), macOS and Windows 10. Supports pen input from devices such as Wacom Tablets.
AthensFree self-hosted desktop app: https://github.com/athensresearch/athens/releases; Try the demo at https://athensresearch.github.io/athens; Docs viewable at https://athensresearch.github.io/docs/
devlogCommand-line tool for tracking your day-to-day software development work
frameNotetaking Electron app that can answer your questions and makes summaries for you
zettelgeistA less-is-more (distributed) notetaking application. Designed specifically for those who prefer working with the command line and want to do crazy indexing, analysis, and transformation of notes. Aimed at but not limited to scholarly research projects.
note-cliMarkdown Indexing and Pcre Regular Expression Compatible Full Text Searching for Advanced Note Takers.
CodexA free note-taking software for programmers and Computer Science students