I have a personal mediawiki that I keep on a raspberry pi home server. It's much better than text files because of the hyperlinking, the history, the statistics and the formatting. It can also be viewed and edited by other family members if I so choose. I guess I could make it available outside the firewall with a password but I haven't really needed that. The cool thing about the PI is everything just works and it consumes almost no power so there isn't a significant ongoing expense to running it once it's set up.