MemberPrism - open source alternative to memberstack / memberspace , but with both front and backend member-only content protection - easychen/MemberPrism2

Tribe.so - Tribe is a white-label platform, empowering the new generation of online communities.

Contentpace - One app to plan, research, brief, optimize & publish better content with AI and workflow automation.

Higher Logic - Private, secure online communities that stimulate conversation and ignite engagement.

Fanfix - Exclusive, behind the scenes content from creators

Basecamp - A simple and elegant project management system.