I'm still using tiddlywiki (tiddlywiki.com), the key features being portability, search, and linking between notes. It's free open source too and has a large community of users who contribute plugins (like LaTex interpreter that I use). I've been using it for 10 years and have found these features to be essential, almost a super power, for the kind of work I do (research). (BTW I believe the name to be a derivative of TLDR, which is the only reasonable thing I can come up with to explain what is otherwise a kind of lame name). Also, worst case you can read the file with a browser, or view it in a terminal since it's essentially markdown. Back it up in Dropbox and you can be sure that you'll never lose it or lose access to it.<p>The downside is that browser security updates almost killed it, since in its simplest implementation it's a single file that lives on your computer, accessed and saved via the browser. Browsers no longer allow modification of local files in a simple way. I found the best method for saving the file, of the several listed on the website, to be to run the Ruby server (a minimal server using Ruby Webrick, point your web browser at <a href="http://localhost:8000" rel="nofollow">http://localhost:8000</a> to view and save the file).<p>Obsidian and DEVONthink look interesting for many of the same reasons, but I don't want to commit to something that dies in a few years (and I'm hesitant to pay). DEVONThink has been around for a long time now however, probably because it's a paid product.