discord.io is described as 'A small, single-file, fully featured Discordapp library for Node.js and browsers' and is an app in the Development category. There are seven alternatives to discord.io for a variety of platforms, including Online / Web-based, Self-Hosted solutions, Windows, Discord and Steam. The best alternative is Discord.js, which is both free and Open Source. Other great apps like discord.io are Eris (Free, Open Source), BotGhost (Freemium), Discord Bot Builder (Paid) and Discordie (Free, Open Source).
discord.js is a powerful node.js module that allows you to interact with the Discord API very easily. It takes a much more object-oriented approach than most other JS Discord libraries, making your bot's code significantly tidier and easier to comprehend.
Discord Bot Builder is an interactive program with a clean and flat user interface that helps people without programming skills to create their Discord Bots. Projects can be exported in a small folder size.
Discord Bot Maker uses a system based on "commands" and "events". Commands are manually called functions that invoke specific actions. These are done by sending specific words or phrases into the chat. The other half of the system involves "events".