grocy is a web-based self-hosted groceries & household management solution for your home.

Tasmota is an open source firmware for ESP8266 based devices.
Total local control with quick setup and updates.
Control using MQTT, Web UI, HTTP or serial.
Automate using timers, rules or scripts.
Integration with home automation solutions.

Rhasspy (pronounced RAH-SPEE) is an open source, fully offline voice assistant toolkit for many languages that works well with Home Assistant, Hass.io, and Node-RED.

Open source home automation that puts local control and privacy first. Powered by a worldwide community of tinkerers and DIY enthusiasts. Perfect to run on a Raspberry Pi or a local server.