For the 100 Day Project, my subject is code.
The 100 Day Project is about process, and my favourite part of writing code is the process. I like building things from the ground up - I like planning phases, interaction design, visual design, and finally, actually building the software (I'm using #100DaysofCode over something like #100DaysofSoftwareDesignandEngineering for brevity).
You've likely read the Pottery Students Parable somewhere - likely making an analogy to building software. I first read it in 101 Things I Learned in Architecture School. This is what I see the 100 Day Project as being about. In doing something every day for 100 days, the goal is to learn through volume and repetition, through throwing things away, and rebuilding.
My primary ongoing side project is called OpenMatter. Its goal is to compile an ongoing listing of open source projects that are welcoming to designers, copywriters, OSS newcomers, and anyone else who wants to get involved in open source. It will provide clear, welcoming entry points for newcomers. The project is close to completion - minimum remaining work includes some front-end, Capistrano deployment to DigitalOcean, and SSL for login. I've been working on moving the project to DigitalOcean from Heroku in order to provide secure login for users without paying $20/month for an SSL add-on, and to say that the process has been painful would be an understatement by orders of magnitude. You'll notice that when I listed various parts of developing software that I enjoy at the beginning of this post, there was no mention of server configuration.
My secondary side project is the Jekyll theme being used on this blog. It's called Terrace, because I bought the very overpriced .io domain terrace.io for OpenMatter, and then changed the name of Terrace to OpenMatter, and so it was only economical to name my next project, Terrace. I'll be using the current version on this blog as I build it out.
For me, #100DaysofCode isn't about the act of typing code into a computer. I don't write code for the sake of writing code. I am a generalist, and I need to start growing the long tail on my T-shape. I need to decide on which specific pieces of the process that I really love. I want to form habits that make it easier for me to be the type of person who can build in their free time. I will be as transparent about my process, and progress as possible, and if you're also participating in the project, I'd love to see your progress too.