GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
Ceremony - Ceremony is the fastest-growing wedding photo collecting application that allows you to easily collect all your wedding pics from guests.
MkDocs - Project documentation with Markdown.
Wedew - Wedding E-invitation & Website
Docusaurus - Easy to maintain open source documentation websites
RegexOne - RegexOne offers learning regular expressions with simple, interactive examples.