Wikis

"This list is incomplete, you can help by expanding it"

Sites which allow people to directly edit them and contribute material, usually with a sign-in required to keep track of contributors.

Games

Games and fun stuff.
Minecraft Wiki
"Minecraft is a 3D sandbox adventure game developed by Mojang Studios where players can interact with a fully customizable three-dimensional world made of blocks and entities."
sekai best
Database of information for mobile game Project Sekai.
Sekaipedia
"Sekaipedia is a wiki dedicated to Project SEKAI: Colorful Stage! (????????? ???????? feat.????), a Japanese mobile rhythm game for iOS and Android. Our goal is to give players all the information they need to enjoy the game, such as story and mechanic translations, card stats, and more. Story and character content translations are also found here."
The Cutting Room Floor
"The Cutting Room Floor is a site dedicated to unearthing and researching unused and cut content from video games. From debug menus, to unused music, graphics, enemies, or levels, many games have content never meant to be seen by anybody but the developers — or even meant for everybody, but cut due to time/budget constraints."
The Spriter's Resource
"This website is a part of several websites under the belt of "The VG Resource" - websites that are dedicated to the collection, archival, and appreciation of materials from video games."
"These resources are collected for personal projects and non-commercial work. Many of our users utilize the sprites, models, textures, and sounds found on our sites to make comics or games and more still just browse them to reminisce on games they’ve played."

Fandom

Wikis about fictional properties, by fans, for fans.
Wikimoon.org
"[An] ongoing project to create a definitive database of information about Sailor Moon."

Other

Miscellaneous other wikis.
Instructables
"Instructables are created by you. No matter who you are, we all have secret skills to share. Come join our community of curious makers, innovators, teachers, and life long learners who love to share what they make."
LGBTQIA Wiki
"The LGBTQIA+ Wiki is a resource of LGBTQIA+ terminology and labels used by various queer communities, as well as the questioning and/or curious. The wiki is designed to be a helpful resource for explaining identities both known and unknown."
Listen to Wikipedia
"Listen to the sound of Wikipedia’s recent changes feed. Bells indicate additions and string plucks indicate subtractions. Pitch changes according to the size of the edit; the larger the edit, the deeper the note."
MOGAI Wiki
"This wiki was made to catalog and organize MOGAI identities. Our goal is to provide an easier way to find the definitions, flags, and creators for niche identities which otherwise may be difficult to find. Check out the discover section below to start diving in and learn more about the wiki."
Mogai Wiki
"You’ve landed at the MOGAI Wiki — An inclusive Wiki on Miraheze for every MOGAI identity, where anyone can edit."
Open Source Innovations
"The mission of Open-Source Innovations is to promote, share ideas, methods, and prototypes for Do-it-Ourselves/DIY adapted mobility devices. There’s a heavy focus in the DME industry on primarily expensive/medical/utilitarian/low performance based mobility solutions . We propose to enable fun and exciting recreational activities through promoting inexpensive performance based adaptive mobility devices."
Parf Edhellen
"This website is dedicated to Tolkien’s languages, with an emphasis on the elvish languages of his legendarium. Our dictionary consists of imported glosses from a variety of quality dictionaries, categorised and searchable by sense, conjugation and more."
Wiktionary
"Welcome to the English-language Wiktionary, a collaborative project to produce a free-content multilingual dictionary. It aims to describe all words of all languages using definitions and descriptions in English."