Spectrum is a community platform for the future. By building on Spectrum, communities become easily discoverable through search, curation, and even other community members.
You may also be interested in ...
Linen
Google-Searchable and community focused Slack alternative. Linen is built for community support. Linen is designed to be familiar to existing communities while giving all the benefits of a forum.
Mattermost
Mattermost is an open source Slack alternative. It's written in Golang and React and runs as a single Linux binary with MySQL or PostgreSQL. Use the features you like (file sharing, real-time group chat and webhooks—to name a few) and access the source code.
Keyv
Keyv is a simple key-value storage with support for multiple backend adapters (MySQL, PostgreSQL, SQLite, Redis, Mongo, DynamoDB, Firestore, Memcached, and more).