This page gives an overview of the RISC-V SW ecosystem.
The extension and feature support of the essential SW ecosystem can be found here: RISC-V extension and feature support in the Open Source SW Ecosystem
An overview about contributing to Toolchain and Runtimes related projects can be found here: How to contribute to the RISC-V SW ecosystem
The lists below link to the status of the RISC-V ports of various SW projects.
Emulators and Simulators
A much bigger, but less detailed and not maintained anymore, collection of SW in the RISC-V ecosystem can be found here: https://github.com/riscv/riscv-software-list