A list and information on various ways to play online.
- Roll20: One of the more popular VTT available. It is a hosted/SaaS service that is browser based so people can play from many different devices. It start out with a free level service and has two higher level subscriptions that add additional storage space and features such as macro and API access.
- Fantasy Grounds: Another very popular VTT. It is a installed application with a server-client architecture so all the data and control is done through the host (GMs) computer. It has both one-time and subscription licensing of two different levels; Standard (all people must have Standard or higher license) and Ultimate (only the GM needs a license).
- Tabletop Simulator: This program isn't specific to RPGs, and approaches VTT in fairly literal manner (there's even a VR option). The cost is $19.99 (but it is frequently on sale for less), and requires each member of your group to purchase the program. After the initial purchase, there are many free options and assets to customize your gaming space for your particular game of choice. There are many free prepackaged sets for playing D&D and other specific RPGs if you don't want to do all the work yourself. Includes its own of VoIP, but can be used in combination with others, like Teamspeak, Discord, etc.
- Astral: Appears to be endorsed by DriveThruRPG. Doesn't seem to natively support D&D, but does list a bunch of other well known RPGs. Free.
- D20PRO. A multi-platform VTT specialized in D&D, Pathfinder, and Starfinder.
- Discord: Private video chat with up to 9 friends.