This page was created March 2020 to provide some quick and useful reference information to clients / which may be useful when remote working is more of a core requirement.
JitSi: https://meet.jit.si/ - this is a free, open source Video Conferencing platform which you could host yourself on your own server platform. Or, use it for free immediately via this server the JitSi team provide. Accessible from any platform, free, no limits, no account/sign up required. Just create a 'meeting room name' and go / share this with participants so they can join you.
WhereBy: https://whereby.com/information/pricing/ Web-browser based collaboration tool for audio/video sharing collaborative working etc. Free 'loss leader' version is very useful if the requirements are good fit for you (smaller meeting sizes) - 1 meeting room, 1 admin user, 4 participants maximum. Since this is a less well known tool it is not suffering as much server lag/burden as Microsoft Teams for example which has had some performance issues lately.
Microsoft Teams: http://teams.microsoft.com/ Microsoft have free(temporary trial, kind of *) and non-free versions of "Teams". If you subscribe already to any MS365 service(s) then you probably have access to teams bundled already, and maybe just don't know it. (It does not install by default with MS365 subscriptions always). This tool is very good for audio and video calls, screen sharing, etc. Note that potentially teams servers are under a lot more stress than normal which can lead to lag / performance issues ( noted - March.20.2020 / Covid19 remote work spike ) (* Currently if you visit the Teams website and indicate interest in "personal free video conferencing" you are redirected to Skype - https://www.skype.com/en/ - which is of course another good option, now also owned by Microsoft, free for personal use and video conferencing etc as core function).
Zoho Remotely: https://www.zoho.com/remotely/?zmc=zoho-fa&ireft=ohome : Zoho are not terribly well known, but for those who do - they have an excellent reputation of providing enterprise-class tools for 'modest' prices. This suite of collaboration tools is currently offered for free (March-July.2020) to support remote teamwork needs for any-all SMBs.
Zoom: https://zoom.us/ : Zoom have been around for a few years already / well established, and very effective-functional solution. Video/Audio conference solutio app with screen share features. They have a free plan (40min max meet length) and various non-free options. Only the organizer must have a zoom account. Cross platform (web, smartphone etc). Possibly will have issues in April 2020, we shall see (ie, have become very!) popular recently.
Google: Google solutions have been around ~quite a long while, nearly not mentioned here because they are so well established and 'well known'. Hangouts - https://hangouts.google.com/ - still around. Participant need a google account to join a meeting (audio/video conference). Google have had a number of tools over the years, and are gradually transitioning away from HangOuts to "Duo" or possibly "messages". Anyhow, if you want, read about it here and use what works well for you: https://blog.google/products/messages/latest-messages-allo-duo-and-hangouts/
3CX Video Conferencing: https://www.3cx.com/phone-system/video-conferencing/ This is not free but an excellent product, and if you have already been deployed on a 3cx server by Fortech IT then you already have access to this feature set 'free of charge' bundled with your 3CX voip phone system.