Command-line shell and scripting language built on .NET
CLI for bluetooth on OSX: power, discoverable state, list, etc.
Tools for BPF-based Linux IO analysis, networking, monitoring, etc.
Kubernetes-native testing framework for test execution
Tools and libraries to glue C/C++ APIs to high-level languages
Lua + libUV + jIT = pure awesomesauce
Open-source, cross-platform, game-development tools
Middleware for distributed applications
Metasploit Framework
Real-time data acquisition and visualization software