Discord

Discord is basically modern day IRC, except it's centralized. It was introduced on 2015-05-13 by the today-eponymous company, Discord Inc. The Discord server and clients are proprietary, the use of Discord is free with paid bonuses.
Discord enables users to create servers (called guilds internally), which further divide into text and voice channels. Those may have different access permissions depending on roles given to users on the server. To note, unlike IRC, Discord keeps unlimited logs of text channels. Anybody who joins a Discord server has access to full server history (except for channels with the seldom used "Read Message History" denial). Access to a Discord server is granted through invites in the forms of an URL, which may be unlimited until disabled or automatically expire.
Discord's status is essentially deep web, as Discord servers are unable to be indexed by conventional search engines and archival tools, even if invites are posted publicly. However, as it keeps history and has a well documented API, it proves possible for users, particularly admins, to create comprehensive archives of servers they have access to.
Should Discord server archives be posted publicly? This is a question worth pondering on. On IRC the implicit agreement is that you don't publish logs, but the privacy story is different on Discord, where everybody who joins gains access to years of logs. Given that closed services like Discord and Telegram are on the road to displace traditional services like message boards, there is culture worth saving. Archival and noindex publication could be appropriate. Note that Discord explicitly forbids collecting and disclosing end user data in their Developer Terms of Service (point 2.4 End User Data). See also our attitude to Robots.txt. Make your call.
== Self-archival ==
Software for archiving Discord servers include:
=== Active ===
Software 	Full	No admin perms	Incremental	GUI Available	Archive format 	Frontend for humans	Platform 	Source code licence
DiscordChatExporter 	 	 	 	 	.txt, .html, .csv, .json	 	C# 	GPLv3
Discord History Tracker 	 	 	 	 	SQL database 	 	C# 	MIT
discard2 	 	 	? 	 	Mitmdump, Wireshark 	? 	TypeScript with Headless Chrome	MIT
XenonA Discord bot intended for server admins to back up servers 	? 	 	? 	? 	? 	? 	Web Service 	?
Discord Backup 	? 	 	? 	 	? 	? 	NodeJS 	MIT
pullcordCreated by ArchiveTeam user moufu. 	 	 	 	 	.tsv 	 	Go 	Unlicense
DiscordChatExporterPyPython plugin for your discord.py bot, allowing you to export a discord channels history within a guild.	? 	 	? 	? 	.html 	 	Python 	GPLv3
Discordlessmitmproxy addon to record and parse Discord traffic 	 	 	 	 	.html, .json 	 	Python 	GPLv3
A URL extractor for some of these archival tools is available here.
Please note that Discord's Developer Policy forbids you from scraping or even just disclosing user data without their consent. Additionally, using "self-bots" (using a user token in automated scripts) is also prohibited, and only the server administrator can add a bot user to the server. Using these tools with your account may get your account banned. Use at your own risk!
=== Tools not yet categorized ===
* discord-dl
* DiscordArchiver
==== Abandoned tools ====
* Zucc was a Discord bot that dumps messages and other data from a guild/server
* discard was a high-fidelity Discord bot client that was compatible with both user and bot tokens.
=== "Make your Discord guild public and searchable" services ===
* Answer Overflow brings discord channels to your favorite search engine if you invite their bot. Also source-available.
==== Abandoned services ====
* Search-Cord was a search engine that could index channels if you invited their bot.
== Discord server aggregators ==
=== Dictionaries ===
* https://disboard.org/ ( on 2019-05-01)
* https://discordbots.org/ ( on 2019-05-01)
* https://discord.me/
* https://blox.link/communities
=== Stat bots ===
* Statbot
=Notes=