Gancio

A free open source collaborative online calendar. It allows local communities to share a common calendar that anyone can post events to, even people without an account. (Posts are moderated to prevent spam though.) You can also interact with Gancio through the Fediverse, and it has RSS support for people who want to follow through feed readers.

Fediverse address:
@gancio@mastodon.cisti.org

Collabora Office

Online fork of the LibreOffice productivity suite aimed at businesses, including long term tech support, admin tools, smartphone apps and cloud collaboration.

Fediverse address:
@CollaboraOffice@mastodon.social

Its development company, Collabora, is one of the biggest upstream contributors to LibreOffice’s source code, and has a close relationship with the FOSS community.

Fediverse address:
@collabora@floss.social