Syncthing replaces proprietary sync and cloud services with something open, trustworthy and decentralized. Your data is your data alone and you deserve to choose where it is stored, if it is shared with some third party and how it's transmitted over the Internet.
With reep.io you can transfer files directly to another browser. Just point to a file you want to share. Your peer will then be able to download this file directly from you. No data is stored on a server in-between.
SD is a peer-to-peer bug tracker that’s built for sharing and use both online and offline. With SD, you can sync your bugs back and forth between other instances of SD, and even between SD and other bug trackers that SD supports (RT / Hiveminder / Trac / GitHub / Google Code).