I code, I like to spend more time look at code, not some blog editor. Using any of these seems like more time wasting,

On the contrary what I'd love is if i could add comments to the source code on github, similar to the way I add comments to the code commits.

I keep all my stuff in .txt files, stored in dropbox. I name them as "Java - blahblah.txt" or "CSS - blahblah.txt"

For searching inside notes, I use agentransack. I find this more efficient and simple.

I really recommend fossil. It integrates a wiki, scm and bug tracker in a single sleek package. Its a single stand-alone <1MB executable and the repo itself is a single sqlite file.