HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
TiddlyWiki - a non-linear personal web notebook
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
Confluence - Confluence is content collaboration software that changes how modern teams work