Free wiki hosting service with focus on flexibility, features and availability. URL format is "http://yourtopic.wikidot.com/". Interactions with other services, extended wiki syntax, uploads, forums, private messaging, access control, feeds.

A free wiki host providing community wiki spaces, visual page editing, and discussion areas.

Free wiki hosting service with proprietary software, GUI editing interface, and instant site registration. URL for wikis is "http://yourtopic.wetpaint.com/".

Free ad-supported wiki hosting with paid upgrades available for educators and businesses. Offers free subdomains, custom domain is a paid feature. Users must create accounts to edit, wiki administrator decides who gets access, ranging from open to the...

Provides wiki and content-managed website hosting.

Free wiki hosting site with text ads, using Open Source XWiki software. URLs in format "http://yourtopic.xwiki.com/". Immediate setup, WYSIWYG editor, photo album, calendar, wikiblog interface.

A collection of freely-hosted ad-supported wiki communities using the Open Source MediaWiki software. URLs like "http://yourtopic.wikia.com/". Requires 2- to 10-day approval process, single sign-on across all Wikia sites, file uploads, transclusion, c...

Free wiki hosting service; custom software includes calendars, photo galleries and spreadsheets. URL format "http://yourtopic.jot.com/". GUI editing, themes, access control.

Offers an Enterprise Wiki as a hosted service or installed on a hardware appliance.

Free wiki hosting service based on DekiWiki. Instant registration, URL format "http://yourtopic.wik.is/". GUI editing, login required to edit. Formerly wiki.com.