Xonsh is a modern, full-featured and cross-platform shell. The language is a superset of Python 3.6+ with additional shell primitives that you are used to from Bash and IPython. It works on all major systems including Linux, OSX, and Windows. Xonsh is meant for the daily use of experts and novices.
The xonsh shell lets you easily mix Python and shell commands in a powerful and simplified approach to the command line.
Github: https://github.com/xonsh/xonsh
Full text indexing and search in go. Index any data object in your software: Text strings, numbers, dates, JSON. Extensible. Aims to have smart defaults. Multiple query types supported, even multiple natural languages. Aims to be easy to use: Three lines of code to index, another three lines to search.
A modular chatops bot written in Python 3 that includes multiple connectors for different services (Slack, Telegram, Github, et al). The databases it can interface with are pretty limited. Skills are plugged into the framework to make it do things (like get status reports).
Selfoss is a personal RSS feed reader written in PHP. The idea is that you install it into a subdirectory of your website or on your laptop, configure it, and use it to read RSS feeds in the same way that you'd use Google Reader (RIP). Can be easily extended with plugins. Supports mobile devices as well as desktop web browsers. Can also import existing OPML feeds (like Google Reader's) to populate the database with what you read. Tiny - 2MB in size.
Err is an extensible XMPP bot framework written in Python. Can connect to XMPP servers just like a client and communicate through them. Implements basic IRC client functionality, can connect to MUCs (Multi-User Chats) on XMPP servers, and supports plugins to extend the functionality of individual bots.