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.
GNU Wget - GNU Wget is a free software package for retrieving files using HTTP(S) and FTP, the most...
TiddlyWiki - a non-linear personal web notebook
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
Confluence - Confluence is content collaboration software that changes how modern teams work