Self-hosted

Focalboard is free, open-source and self-hosted.

Wiki.js is free and open source, built upon Node.js. It saves all content directly in Markdown (.md) files and syncs with your remote Git repository.

Cross-platform continuous integration solution, the free version offers a generous amount of 100 build configurations and 3 concurrent builds. Newer versions provide conditional build steps and Prometheus metrics (monitoring system and time series database).

Great for monitoring info, with pre-built widgets

It is a fresh breeze in CI/CD area. Most tools like that are only focused on simple command-line execution and do not consume results or do much analysis of them.

Straightforward install, easy to adapt search for different languages or media types

Awesome software with Simple GUI

Self hosted, supports Windows, Mac, Raspberry Pi and Linux servers. See review : https://arstechnica.com/information-technology/2012/09/make-all-your-data-available-on-any-device-no-cloud-required/.