Since you mentioned emacs, org-mode has the ability to attach files and show image files within the buffer, and it handles previewing latex formulas too. The p

Since you mentioned emacs, org-mode has the ability to attach files and show image files within the buffer, and it handles previewing latex formulas too. The problem with these kind of system is that you always need the emacs open, because opening emacs and find the org file you want is too much a friction comparing to opening up a note book and start writing/doodling.