Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

1. Zoom

Best choice for enterprise. However, Zoom provides only 40-minute meetings for the "Free" plan.

1. Microsoft Teams

A great choice.

1. Slack

another very good choice

1. Skype

   • support screen sharing

2. WeChat

   • do not support screen sharing

3. QQ

   • support screen sharing

4. Apache OpenMeeting

5. Jitsi

6. iVisit, iChat, NetMeeting

7. Breeze

8. GoToMeeting (free for up to 4 people)

9. Google Voice (up to 4 people)

10. FreeConferenceCall (seems that it is free?)

11. Wiggio (?)

12. Speek (?)

13. https://www.freeconference.com/

14. join.me by LogMeIn

15. SightSpeed

16. Free conference calling

17. Dimdim

18. Tokbox

19. MyMeeting123

20. Paltalk

21. MegaMeeting

22. Fuze Meeting

23. Free Audio Conferencing

24. Easy Conference

25. Easy Conference

26. Gizmo Call

27. Totally Free Conference

28. RingCenteral

29. Onstream Meetings

References

http://en.wikipedia.org/wiki/Comparison_of_web_conferencing_software

http://www.d.umn.edu/~hrallis/professional/presentations/cotfsp06/indiv_tools/videoaudio.htm

http://blogs.skype.com/2013/06/18/conference-calling-with-skype-quick-easy-and-cost-effective/