Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Bashupload - Upload files from command line to share between servers
Airborn - Create and edit documents online without sacrificing your privacy
FilePizza - Open source application used to transfer file via WebRTC and WebTorrent.
Bit.ai - Bit is a smart real-time document collaboration platform for teams to create interactive documents, manage digital content and track document insights.
BlackHole File Transfer - Blockchain-based file transfer. Designed for everyday use.