Inspiration
Needed some inspiration for ideas or projects (or just want to get some things done)? Here's some of the resources that offers that.
Build Your Own X (by danistefanovic)
A list of resources for building your own version of a technology from programming languages, 3D renderers, bots, games, and text editors.
Dribbble
If you want some inspiration for some design-related projects, here's a community site of designers that share their own work.
OS Tutorial (by cfenollosa)
A GitHub repo that contains a tutorial on making your own operating system from scratch.
OSDev.org
A detailed wiki on operating system development.
Product Hunt
A platform for finding and exploring products made from a wide variety of people and organizations who create a product.
Project Based Learning (by tuvtran)
A GitHub repo that offers a curated list for project-based learning. If you're the type of person who's quite comfortable learning by doing, have a quick go.
Projects (by karan)
A GitHub repo of a project list.
Rosetta Code Programming Tasklist
It's a humungous list of programming tasks that you can do ranging from intermediate to advanced thinking and planning skills to get the job rolling.
Personal comment:
You can also make a project based on the things that listed here. Think of it like a fork of the project.