Hot answers tagged note-taking
I would suggest to use TagSpaces. It is open source, and allows editing and tagging of multiple file types. It also enables different views like you mentioned. The best thing about it in my opinion is that you can use it with any cloud storage you like.
From your requirements above, it would seem that Trello may be a good solution to your preferred organization system. A single Trello 'board' contains a system of 'lists' which can contain unlimited 'cards'. Each card can contain a variety of content including tags, links, files, etc. And Trello can very easily be setup for GTD use.
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