Calamus is described as 'A map-making companion for tabletop RPGs, like Dungeons & Dragons or Pathfinder' and is a Virtual Tabletop in the category. There are more than 25 alternatives to Calamus for a variety of platforms, including Online / Web-based, Windows, Mac, Linux and Android. The best alternative is Roll20, which is free. Other great apps like Calamus are D&D Beyond (Freemium), Inkarnate (Freemium), Foundry Virtual Tabletop (Paid) and MapTool (Free, Open Source).
Beyond Tabletop is a set of tools for RPG players with easy-to-use online character sheets and maps. Subscription-free and designed to be used on all devices online. Currently offering a battle map and character sheets for Pathfinder and D&D 5e.
Rolisteam helps you to manage tabletop role playing games with remote friends/players. It provides many features to share maps, pictures and it also includes tool to communicate with your friends/players.
Rolz offers free tools for rolling dice for RPG players and dungeon masters featuring scores of randomization tools including random name and character generators and an API for developers to make use of those tools.
TaleSpire is an online, digital, graphical way of playing classic P&P Role-playing games with your friends. As a DM, build your campaign in-game and invite your players for sessions. To your left you can watch one of our streams to see for yourself.
PlanarAlly is a web tool that adds virtual battlemaps with various extras to your D&D toolbox.
Self hosting, Offline support, Simple layers, Infinite canvas, Dynamic lighting, Player vision, Initiative tracker.
Free to use and is open source.
Battlegrounds: RPG Edition (aka BRPG) is virtual tabletop software designed to enhance your pen-and-paper roleplaying games, whether your players are in the same room, or on the other side of the world.
Digital d20 is a platform for distributing and playing adventures in a new digital format that aims to change the way the adventures are prepared and ran, with the help of new technologies, but maintaining the romanticism of paper and pencil.