- Chat: (short) text messages are sent back and forth. All participants see all messages. Simple, currently present in any social network program. Technical requirements are nihil/non-existent.
- Audio / video conferencing: all participants hear / see each other. Technically, there are hardly any barriers to the use of audio / video conferencing tools today: Virtually all PCs, tablets, … are equipped with microphone and webcam, and there are plenty of (free) tools available. Examples include Skype and Team Viewer.