BookStack
Description: BookStack is an open source knowledge management platform to help build and organize wikis for internal or public use. It allows you to collaboratively write and structure documents to organize knowledge, notes or documentation.
Type: software
Pricing: Free
Yahoo! Messenger
Description: Yahoo! Messenger is an instant messaging client and associated protocol provided by Yahoo!. It allows users to communicate in real-time through text, voice, video chat, and file sharing. Popular in the early 2000s, it has since declined in usage with the rise of smartphones and other messaging apps.
Type: software